1 core 878042  years  1850 1990 number  141
     2 core JAH021  years  1850 1991 number  142
     3 core JAH081  years  1718 1991 number  274
     4 core JAH131  years  1825 1991 number  167
     5 core JAH141  years  1662 1988 number  327
     6 core JAH151  years  1573 1988 number  416
     7 core JAH162  years  1681 1988 number  308
     8 core JAH171  years  1719 1988 number  270
     9 core JAH211  years  1762 1988 number  227
    10 core JAH221  years  1751 1982 number  232
    11 core JAH231  years  1710 1988 number  279
    12 core M021    years  1628 1963 number  336
    13 core M121    years  1678 1963 number  286
    14 core M202    years  1657 1963 number  307
    15 core M331    years  1721 1963 number  243
    16 core M371    years  1680 1963 number  284
    17 core X02S    years  1721 1982 number  262
    18 core X13     years  1639 1978 number  340
    19 core X14W    years  1668 1982 number  315
    20 core X16S    years  1695 1982 number  288