| Table 2. Estimated stock numbers. | |||||||
| Year\Age | 1 | 2 | 3 | 4 | 5 | 6 | 7+ |
| 1963 | 454067 | 190804 | 21066 | 10330 | 8416 | 3271 | 1616 |
| 1964 | 810981 | 139107 | 53210 | 11618 | 5284 | 4579 | 2253 |
| 1965 | 1051786 | 244507 | 41274 | 23110 | 6340 | 2567 | 3041 |
| 1966 | 1360006 | 289526 | 69703 | 16609 | 9668 | 3305 | 2866 |
| 1967 | 1226899 | 362580 | 74161 | 28825 | 7873 | 4713 | 3271 |
| 1968 | 637303 | 319017 | 91950 | 28254 | 14213 | 3431 | 3508 |
| 1969 | 565237 | 156686 | 76039 | 33996 | 11260 | 6652 | 3072 |
| 1970 | 1803068 | 143631 | 40296 | 32338 | 15346 | 4672 | 3972 |
| 1971 | 2380926 | 445076 | 35066 | 15024 | 15709 | 6760 | 4140 |
| 1972 | 562980 | 561856 | 93995 | 12205 | 6091 | 6785 | 5550 |
| 1973 | 830680 | 123995 | 110636 | 29584 | 4982 | 2528 | 4531 |
| 1974 | 719995 | 182590 | 24294 | 36644 | 11020 | 2177 | 3200 |
| 1975 | 1249183 | 169058 | 37760 | 9659 | 16350 | 4621 | 2303 |
| 1976 | 792541 | 287794 | 34441 | 13710 | 3966 | 6864 | 2791 |
| 1977 | 2043143 | 168215 | 52628 | 11040 | 5286 | 1773 | 4101 |
| 1978 | 1233048 | 443299 | 31288 | 18721 | 5323 | 2290 | 2291 |
| 1979 | 1454249 | 262761 | 81716 | 9193 | 7247 | 1800 | 1794 |
| 1980 | 2412080 | 297747 | 59042 | 25059 | 4043 | 2842 | 1730 |
| 1981 | 949794 | 478782 | 59042 | 17844 | 9094 | 1661 | 1856 |
| 1982 | 1506049 | 183139 | 92226 | 17129 | 6702 | 3830 | 1483 |
| 1983 | 838190 | 287506 | 32827 | 21688 | 5549 | 2462 | 1852 |
| 1984 | 1597579 | 165380 | 51431 | 8191 | 6911 | 2052 | 1618 |
| 1985 | 388093 | 323838 | 33157 | 14897 | 2882 | 2652 | 1400 |
| 1986 | 1846865 | 83117 | 58747 | 10356 | 5598 | 1162 | 1654 |
| 1987 | 700816 | 398714 | 16319 | 15550 | 3143 | 2008 | 1052 |
| 1988 | 479740 | 157157 | 70193 | 5152 | 5011 | 1238 | 971 |
| 1989 | 833176 | 109316 | 30577 | 17415 | 1801 | 1896 | 840 |
| 1990 | 340783 | 186465 | 20189 | 7855 | 5105 | 635 | 939 |
| 1991 | 383464 | 79858 | 30884 | 5975 | 2616 | 1926 | 695 |
| 1992 | 806936 | 92781 | 14851 | 8418 | 1961 | 918 | 862 |
| 1993 | 373249 | 194853 | 17508 | 4765 | 2675 | 722 | 608 |
| 1994 | 892695 | 95703 | 33996 | 5127 | 1619 | 942 | 465 |
| 1995 | 569207 | 223686 | 21358 | 9578 | 1674 | 604 | 489 |
| 1996 | 366590 | 139246 | 37160 | 5394 | 3033 | 635 | 463 |
| 1997 | 1181151 | 96086 | 25336 | 9128 | 1823 | 1011 | 358 |
| 1998 | 141775 | 297152 | 20080 | 6820 | 2791 | 644 | 416 |
| 1999 | 279288 | 37647 | 51328 | 5174 | 1971 | 825 | 406 |
| 2000 | 530195 | 71539 | 8411 | 10223 | 1433 | 582 | 326 |
| 2001 | 182225 | 138413 | 14233 | 2219 | 2296 | 333 | 274 |
| 2002 | 266999 | 50111 | 25797 | 3899 | 589 | 591 | 177 |
| 2003 | 136080 | 69773 | 10469 | 7156 | 1060 | 171 | 216 |
| 2004 | 215561 | 38177 | 13782 | 2978 | 1896 | 306 | 111 |
| 2005 | 156061 | 55326 | 7790 | 3386 | 916 | 600 | 130 |
| 2006 | 357897 | 44135 | 11420 | 2079 | 957 | 303 | 242 |
| 2007 | 160974 | 95894 | 9171 | 3671 | 832 | 306 | 166 |
| 2008 | 196222 | 43915 | 21110 | 2926 | 1365 | 362 | 185 |
| 2009 | 194464 | 52261 | 10407 | 6868 | 1151 | 453 | 181 |
| 2010 | 296855 | 53477 | 12065 | 3631 | 2580 | 381 | 186 |
| 2011 | 156530 | 79618 | 12743 | 4036 | 1455 | 947 | 190 |
| 2012 | 195243 | 43958 | 20315 | 5819 | 1662 | 598 | 406 |
| 2013 | 225258 | 50061 | 12094 | 9343 | 2875 | 684 | 418 |
| 2014 | 258849 | 56500 | 13680 | 6033 | 4652 | 1458 | 541 |