| Table 2. Estimated stock numbers. | |||||||
| Year\Age | 1 | 2 | 3 | 4 | 5 | 6 | 7+ | 
| 1963 | 397520 | 205664 | 21532 | 9878 | 8086 | 2986 | 1459 | 
| 1964 | 434521 | 121176 | 53104 | 11221 | 4983 | 4224 | 2041 | 
| 1965 | 1527282 | 181135 | 37647 | 22471 | 6019 | 2448 | 2871 | 
| 1966 | 1735837 | 339422 | 60718 | 15913 | 9698 | 3106 | 2654 | 
| 1967 | 1183516 | 388481 | 78433 | 27174 | 7583 | 4632 | 2958 | 
| 1968 | 622812 | 326440 | 94750 | 28339 | 13537 | 3402 | 3394 | 
| 1969 | 224583 | 141351 | 79142 | 34683 | 11417 | 6336 | 2997 | 
| 1970 | 1795870 | 96761 | 38025 | 32145 | 15297 | 4763 | 3936 | 
| 1971 | 3166065 | 470711 | 29407 | 14498 | 15154 | 6786 | 4088 | 
| 1972 | 528078 | 664639 | 95894 | 11544 | 6155 | 6696 | 5359 | 
| 1973 | 991526 | 125744 | 121297 | 30424 | 4952 | 2605 | 4724 | 
| 1974 | 992518 | 205253 | 25694 | 39144 | 11399 | 2148 | 3202 | 
| 1975 | 1460077 | 186093 | 40215 | 9593 | 16627 | 4713 | 2283 | 
| 1976 | 1307987 | 343863 | 36098 | 13919 | 4013 | 6998 | 2866 | 
| 1977 | 2999631 | 228205 | 57526 | 11566 | 5463 | 1744 | 4117 | 
| 1978 | 646934 | 557379 | 35242 | 19122 | 5198 | 2322 | 2370 | 
| 1979 | 2383308 | 197205 | 91035 | 9971 | 7424 | 1874 | 1883 | 
| 1980 | 4214325 | 349410 | 51689 | 25591 | 4104 | 2864 | 1708 | 
| 1981 | 936589 | 586542 | 64344 | 16641 | 9452 | 1666 | 1885 | 
| 1982 | 1441219 | 169397 | 99310 | 16895 | 6548 | 3869 | 1493 | 
| 1983 | 583617 | 284361 | 32925 | 21502 | 5491 | 2530 | 1967 | 
| 1984 | 2094866 | 148747 | 54285 | 8070 | 6792 | 2069 | 1673 | 
| 1985 | 323191 | 346625 | 33827 | 15870 | 2916 | 2636 | 1416 | 
| 1986 | 2388079 | 74236 | 62131 | 10339 | 5629 | 1151 | 1618 | 
| 1987 | 478303 | 431059 | 16712 | 15689 | 3270 | 2037 | 1038 | 
| 1988 | 345242 | 134592 | 75207 | 5150 | 5024 | 1269 | 1025 | 
| 1989 | 1050734 | 92967 | 30607 | 17712 | 1797 | 1915 | 862 | 
| 1990 | 313640 | 215346 | 20117 | 7915 | 5184 | 653 | 985 | 
| 1991 | 356825 | 74982 | 35561 | 5931 | 2617 | 1940 | 678 | 
| 1992 | 862853 | 90219 | 15923 | 9124 | 1966 | 948 | 899 | 
| 1993 | 374370 | 203618 | 19604 | 5193 | 2966 | 760 | 662 | 
| 1994 | 1451343 | 96955 | 37760 | 5415 | 1726 | 1011 | 489 | 
| 1995 | 545250 | 289816 | 22675 | 9912 | 1692 | 617 | 505 | 
| 1996 | 262236 | 144784 | 49961 | 6099 | 3379 | 674 | 476 | 
| 1997 | 1206218 | 95511 | 31825 | 11253 | 2195 | 1214 | 408 | 
| 1998 | 156686 | 346279 | 25135 | 8334 | 3442 | 818 | 544 | 
| 1999 | 283509 | 40095 | 64991 | 5803 | 2262 | 985 | 475 | 
| 2000 | 438450 | 73204 | 9610 | 10825 | 1450 | 611 | 375 | 
| 2001 | 112533 | 129703 | 15596 | 2016 | 2114 | 312 | 261 | 
| 2002 | 236570 | 35454 | 29614 | 3848 | 558 | 548 | 174 | 
| 2003 | 86077 | 58865 | 10163 | 6430 | 1005 | 148 | 186 | 
| 2004 | 175255 | 26423 | 13577 | 2997 | 1992 | 291 | 126 | 
| 2005 | 131663 | 46958 | 7266 | 3307 | 912 | 696 | 133 | 
| 2006 | 327748 | 34752 | 12611 | 2135 | 947 | 301 | 279 | 
| 2007 | 166875 | 93153 | 9916 | 3666 | 827 | 324 | 194 | 
| 2008 | 141917 | 42873 | 26450 | 2991 | 1418 | 335 | 221 | 
| 2009 | 145365 | 43783 | 11570 | 7250 | 1182 | 506 | 209 | 
| 2010 | 213416 | 47287 | 13661 | 3610 | 2717 | 442 | 237 | 
| 2011 | 96955 | 72186 | 14880 | 4018 | 1415 | 1082 | 223 | 
| 2012 | 290106 | 33928 | 26635 | 5381 | 1578 | 560 | 453 |