| Table 2. Estimated stock numbers. | ||||||||
| Year\Age | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10+ | 
| 1967 | 95703 | 63959 | 53477 | 7079 | 5224 | 1239 | 785 | 725 | 
| 1968 | 123748 | 76115 | 47620 | 28453 | 2971 | 2045 | 639 | 748 | 
| 1969 | 184795 | 70123 | 46537 | 28681 | 20113 | 2871 | 2059 | 711 | 
| 1970 | 187587 | 195634 | 44267 | 35348 | 16508 | 9674 | 1587 | 1370 | 
| 1971 | 268874 | 153584 | 109098 | 19361 | 17123 | 10750 | 6889 | 2539 | 
| 1972 | 170416 | 176487 | 84373 | 62442 | 12184 | 10033 | 6225 | 5845 | 
| 1973 | 170246 | 96664 | 90039 | 54122 | 30001 | 7259 | 5057 | 7795 | 
| 1974 | 175080 | 82207 | 42235 | 58279 | 40135 | 17117 | 4663 | 6885 | 
| 1975 | 174905 | 69355 | 31382 | 21511 | 34787 | 24392 | 10339 | 7605 | 
| 1976 | 416649 | 102744 | 29086 | 16468 | 11610 | 16737 | 11412 | 10168 | 
| 1977 | 98027 | 145074 | 35668 | 12574 | 8770 | 7430 | 10138 | 12831 | 
| 1978 | 113437 | 67373 | 56275 | 12698 | 4382 | 3669 | 2996 | 12139 | 
| 1979 | 69286 | 48874 | 34857 | 29173 | 8021 | 2600 | 2049 | 8615 | 
| 1980 | 66970 | 38677 | 25135 | 19516 | 17002 | 3960 | 1699 | 7956 | 
| 1981 | 121176 | 31226 | 21634 | 11566 | 9792 | 9078 | 2180 | 7060 | 
| 1982 | 109316 | 97734 | 21444 | 15189 | 6032 | 4589 | 3497 | 4180 | 
| 1983 | 100609 | 53423 | 54885 | 11391 | 9225 | 3133 | 2517 | 3522 | 
| 1984 | 221904 | 64731 | 26503 | 24984 | 4249 | 3211 | 1081 | 2176 | 
| 1985 | 338067 | 105768 | 27778 | 11571 | 8335 | 1884 | 1229 | 1951 | 
| 1986 | 202197 | 151448 | 30699 | 11556 | 6022 | 3834 | 1041 | 2036 | 
| 1987 | 106938 | 165380 | 32630 | 8767 | 4739 | 3104 | 2064 | 1619 | 
| 1988 | 113437 | 58513 | 66436 | 9687 | 4247 | 2466 | 1688 | 1635 | 
| 1989 | 82702 | 64023 | 26108 | 23295 | 4046 | 1861 | 1074 | 1309 | 
| 1990 | 143200 | 44223 | 24810 | 10851 | 8014 | 2034 | 839 | 1060 | 
| 1991 | 155749 | 67373 | 16661 | 9730 | 4902 | 3205 | 1038 | 1147 | 
| 1992 | 88080 | 81471 | 26108 | 7521 | 4600 | 2339 | 1596 | 1206 | 
| 1993 | 195438 | 58513 | 31070 | 8199 | 3337 | 3013 | 1753 | 2178 | 
| 1994 | 117008 | 109754 | 30884 | 12898 | 2986 | 1246 | 1222 | 2143 | 
| 1995 | 176487 | 74832 | 41028 | 12533 | 7358 | 1664 | 1071 | 1943 | 
| 1996 | 88876 | 132588 | 31163 | 19274 | 7835 | 2751 | 727 | 1398 | 
| 1997 | 124492 | 71325 | 89769 | 12067 | 7878 | 3198 | 1011 | 955 | 
| 1998 | 82868 | 109974 | 47099 | 53852 | 7754 | 4093 | 1823 | 964 | 
| 1999 | 80258 | 51380 | 77111 | 27092 | 32533 | 5524 | 2337 | 1791 | 
| 2000 | 89680 | 87204 | 32209 | 47193 | 14377 | 15646 | 2569 | 1736 | 
| 2001 | 213203 | 78984 | 81471 | 16009 | 20296 | 8908 | 7770 | 1422 | 
| 2002 | 178796 | 182408 | 38677 | 40864 | 8831 | 11338 | 5733 | 5520 | 
| 2003 | 116774 | 101215 | 98617 | 22248 | 24984 | 5379 | 6230 | 4280 | 
| 2004 | 67373 | 80660 | 73130 | 55659 | 14573 | 15021 | 3621 | 3633 | 
| 2005 | 137999 | 54122 | 60779 | 63640 | 41523 | 10624 | 8610 | 2444 | 
| 2006 | 95511 | 123871 | 41028 | 34235 | 39616 | 21307 | 6362 | 5765 | 
| 2007 | 194658 | 44712 | 90672 | 27557 | 21239 | 18531 | 9266 | 5152 | 
| 2008 | 99608 | 117595 | 27474 | 62069 | 18387 | 13115 | 10867 | 8114 | 
| 2009 | 74533 | 51380 | 51072 | 15935 | 33090 | 13325 | 9104 | 12720 | 
| 2010 | 96955 | 39458 | 26957 | 20992 | 9138 | 16142 | 8585 | 15429 | 
| 2011 | 98913 | 90490 | 22765 | 14769 | 9240 | 5053 | 10024 | 16500 | 
| 2012 | 84796 | 43088 | 63959 | 14158 | 7896 | 4464 | 2269 | 13643 | 
| 2013 | 72548 | 93153 | 20145 | 32630 | 8162 | 4905 | 2860 | 8725 | 
| 2014 | 40741 | 63259 | 58163 | 13782 | 18977 | 5021 | 2544 | 7493 |