100 post sixpence - frequency analysis of year types in random sample

Discussion in 'Numismatics' started by THUCYDIDES79, Apr 21, 2011.

  1. THUCYDIDES79

    THUCYDIDES79 New Member Silver Stacker

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    [​IMG]
    Hello Guys,

    I recently bought 100 post sixpence coins from SilverAM ( thanks !!! ;) )

    And since the long weekend began and i kinda have time and willingness to do it,
    so i wrote down all the mintages ( rounded to nearest 100k & excluding proof issues which had extremely low mintage numbers and Melbourne, Perth & Sydney mints and
    is beyond the scope of this quick little study )

    Anyways

    Australian Sixpence

    2.82 grams 0.500 Ag 0.0453 oz asw ( as per Krause - our calc on the site has 0.0455 by the way - im going by Krause )



    1946 : 10.0 mill
    1947 : NONE MINTED
    1948 : 1.6 mill
    1949 : NONE MINTED
    1950 :10.3 mill
    1951 : m 13.8 mill & PL 20.0 mill ( m & PL 2 diff mints ) assumed as 33.8 mill total for 1951
    1952 : 2.1 mill
    1953 : 1.1 mill
    1954 : 7.7 mill
    1955 : 14.2 mill
    1956 : 7.9 mill
    1957 : 13.8 mill
    1958 : 17.9 mill
    1959 : 11.7 mill
    1960 : 18.6 mill
    1961 : 9.2 mill
    1962 : 44.8 mill
    1963 : 25.1 mill




    FOTOS below


    [​IMG]

    [​IMG]


    back to years and calculations,

    So total number of all coins T ( from table above )
    number of years in which minted y

    T = 230 mill
    y = 16 year types

    See below for frequency occurance ( excluding coins which have been melted back, or lost or have left the country - no info on that by the way )
    frequency is 2nd column, and 3 column is from silverAMs purchase




    1946 : 10.0 mill 4.34% 2 coins
    1947 : NONE MINTED
    1948 : 1.6 mill 0.69 %
    1949 : NONE MINTED
    1950 :10.3 mill 4.47 % 2 coins
    1951 : m 13.8 mill & PL 20.0 mill ( m & PL 2 diff mints ) assumed as 33.8 mill total for 1951 14.69 % 13 coins
    1952 : 2.1 mill 0.91 % 1 coin
    1953 : 1.1 mill 0.47 %
    1954 : 7.7 mill 3.34 %
    1955 : 14.2 mill 6.17 %
    1956 : 7.9 mill 3.43 % 6 coins
    1957 : 13.8 mill 6.00 % 7 coins
    1958 : 17.9 mill 7.78 % 7 coins
    1959 : 11.7 mill 5.08 %
    1960 : 18.6 mill 8.08 % 18 coins
    1961 : 9.2 mill 4.00 % 3 coins
    1962 : 44.8 mill 19.47 % 26 coins
    1963 : 25.1 mill 10.91 13 coins

    note 1 coin was 1945 ( which is pre so had almost double the asw )

    As can be seen from above table 1953 would be the KEY mintage year as 6p coined in that year are about 40 times
    rarer than highest mintage yar 1962

    So highest mintage years and thus the most abundant coins are


    1962
    1951
    1963
    1960
    1958
    1957
    .
    .
    .

    So these 6 years ( out of 16 total ) compose about 66.95 % of total post 6p on issue.



    So this would be the first of hopefully more aussie numismatic installments from thucy.
    Hard to find the time.
    But above info can be nicely analysed on spreadsheets and models can be calculated by
    looking at completed listings on eBay for rarer coins - or the same model on Florins
    The Florins by the way are the perfectly suited Coin Series for such analysis due to the fact
    that they have a number of rare types ( the Parliament issue at 2 mill , and the Victoria & Melbourne issue at 54k mintage where it is known that
    21k were melted - whereas the TOTAL NUMBER OF MINTED STERLING FLORINS was larger than 100 MILLION )


    Thus the Parliament issue ( 2 mill out of 100+ mill so less than 2% of total minted )

    [imgz=http://forums.silverstackers.com/uploads/531_canberra_florin_2_s.jpg][​IMG][/imgz]
    source http://ookaboo.com/o/pictures/topic/15739/Old_Parliament_House_Canberra

    &

    The Centennial of Victoria and Melbourne issue is even rarer ( 33k surviving out of 100+ mill so less than 0.033 % )

    [imgz=http://forums.silverstackers.com/uploads/531_victoriamelbourneflorin.gif][​IMG][/imgz]
    source http://museumvictoria.com.au/discoverycentre/infosheets/melbourne-mint/


    The low mintage years are by orders of magnitude smaller than total number of coins minted !

    ...

    Thats would be it for this first installment - i dont know if and when there will be more :)t79

    Hope it was educational & enjoyable

    :)
     
  2. kilo

    kilo Well-Known Member Silver Stacker

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    Very interesting, nothing like sorting a bag of coins i reccon, look foward to your next instalment!
     
  3. THUCYDIDES79

    THUCYDIDES79 New Member Silver Stacker

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    As I was sorting them out I remembered PROJACK who mentioned once, that a few years ago
    he was sorting out 50kg of predecimal aussie silver that he bought for $5k in around 2007 !!!
    and his wife refered to it as JUNK hehe

    Had my one walked in on me she would have refered to me as CHILD hehe
     
  4. kilo

    kilo Well-Known Member Silver Stacker

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    let the child within play i say!
     
  5. Austacker

    Austacker Active Member

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    That is a good summary Thucy, it generally works out that the higher mintage's give you the most in the batch you collect. When sorted you can quite easily guess what are the higher mintage's.

    As for the accuracy I think that many of these numbers now are so skewed that they really offer no real relevance to numbers in existence. Sure it tells what originally where rare and they are the key ones straight away. However there was so much coinage melted, sold, exported that to say that any year now could be very rare is a possibility so references like these make it interesting to see if any large mintage's now are actually a little rarer than at first.

    As per your example the 55, 59 with high mintage's none where in the mix, again a lot of this is random as well, but really appreciate seeing a direct result and comparison.
     

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