| Table 2. Estimated stock numbers. | |||||||
| Year\Age | 1 | 2 | 3 | 4 | 5 | 6 | 7+ | 
| 1963 | 509915 | 182956 | 20244 | 10361 | 8394 | 3328 | 1604 | 
| 1964 | 846614 | 139525 | 51637 | 11430 | 5296 | 4602 | 2345 | 
| 1965 | 1048635 | 238709 | 41151 | 22471 | 6286 | 2534 | 3208 | 
| 1966 | 1305374 | 276786 | 69010 | 16732 | 9349 | 3244 | 2826 | 
| 1967 | 1090340 | 346625 | 72548 | 29231 | 7984 | 4688 | 3067 | 
| 1968 | 569207 | 290977 | 90581 | 28141 | 14423 | 3462 | 3490 | 
| 1969 | 505347 | 147119 | 72114 | 34098 | 11225 | 6749 | 3065 | 
| 1970 | 1581683 | 135537 | 39262 | 32177 | 15260 | 4626 | 4210 | 
| 1971 | 2047234 | 415401 | 34064 | 14973 | 15921 | 6624 | 4136 | 
| 1972 | 506865 | 518140 | 91035 | 12254 | 6045 | 6927 | 5093 | 
| 1973 | 734540 | 118184 | 106617 | 29525 | 4976 | 2511 | 4758 | 
| 1974 | 723604 | 174730 | 23576 | 37049 | 10916 | 2179 | 3159 | 
| 1975 | 1172912 | 170076 | 36754 | 9511 | 16561 | 4637 | 2304 | 
| 1976 | 802912 | 270493 | 34683 | 13486 | 3898 | 6839 | 2851 | 
| 1977 | 2039061 | 165215 | 50615 | 11438 | 5187 | 1763 | 4033 | 
| 1978 | 1375049 | 434087 | 30669 | 18503 | 5588 | 2251 | 2342 | 
| 1979 | 1616866 | 277340 | 80017 | 9199 | 7195 | 1781 | 1796 | 
| 1980 | 2607754 | 310830 | 59338 | 24612 | 4031 | 2805 | 1606 | 
| 1981 | 1065548 | 492377 | 58747 | 17778 | 8817 | 1633 | 1805 | 
| 1982 | 1691286 | 193687 | 92689 | 16948 | 6644 | 3774 | 1411 | 
| 1983 | 943168 | 308970 | 33390 | 21320 | 5423 | 2415 | 1846 | 
| 1984 | 1623346 | 174033 | 51689 | 8084 | 6787 | 2003 | 1568 | 
| 1985 | 422101 | 313953 | 32598 | 14765 | 2801 | 2573 | 1354 | 
| 1986 | 1804872 | 85050 | 56840 | 9958 | 5598 | 1129 | 1561 | 
| 1987 | 708567 | 373249 | 16372 | 15233 | 3059 | 2020 | 986 | 
| 1988 | 486018 | 150995 | 70123 | 5135 | 4942 | 1206 | 1017 | 
| 1989 | 775296 | 106085 | 29912 | 17240 | 1813 | 1875 | 810 | 
| 1990 | 323191 | 168215 | 20042 | 7795 | 4978 | 620 | 937 | 
| 1991 | 362217 | 73939 | 29496 | 5946 | 2629 | 1912 | 625 | 
| 1992 | 779182 | 86250 | 14523 | 8430 | 1980 | 920 | 865 | 
| 1993 | 412091 | 183322 | 16669 | 4629 | 2639 | 713 | 610 | 
| 1994 | 881165 | 101215 | 33557 | 5018 | 1583 | 937 | 464 | 
| 1995 | 534988 | 214272 | 21380 | 9358 | 1607 | 573 | 491 | 
| 1996 | 351512 | 128669 | 35242 | 5284 | 2957 | 610 | 407 | 
| 1997 | 1018661 | 90853 | 23981 | 8774 | 1736 | 978 | 336 | 
| 1998 | 137585 | 265136 | 18943 | 6350 | 2652 | 584 | 411 | 
| 1999 | 237518 | 36026 | 48002 | 4890 | 1822 | 790 | 345 | 
| 2000 | 428052 | 63959 | 7950 | 9449 | 1321 | 523 | 312 | 
| 2001 | 161781 | 118777 | 13285 | 2074 | 2129 | 311 | 245 | 
| 2002 | 229349 | 46212 | 23671 | 3648 | 556 | 560 | 164 | 
| 2003 | 120451 | 63640 | 9948 | 6561 | 972 | 162 | 210 | 
| 2004 | 190995 | 36026 | 13298 | 2924 | 1825 | 296 | 112 | 
| 2005 | 151752 | 52208 | 7822 | 3337 | 935 | 599 | 132 | 
| 2006 | 341465 | 44267 | 11768 | 2217 | 995 | 331 | 248 | 
| 2007 | 163407 | 96664 | 9521 | 3838 | 890 | 323 | 188 | 
| 2008 | 185350 | 45433 | 22203 | 3083 | 1387 | 377 | 187 | 
| 2009 | 184057 | 51175 | 10578 | 7027 | 1187 | 462 | 185 | 
| 2010 | 270222 | 51586 | 11947 | 3573 | 2615 | 385 | 198 | 
| 2011 | 142201 | 73204 | 12123 | 3887 | 1392 | 942 | 196 | 
| 2012 | 201390 | 39301 | 18099 | 5308 | 1531 | 564 | 416 | 
| 2013 | 240867 | 52839 | 10532 | 8012 | 2376 | 583 | 382 | 
| 2014 | 356825 | 60476 | 15377 | 4930 | 3652 | 962 | 382 | 
| 2015 | 264607 | 92781 | 16868 | 7294 | 2453 | 1767 | 647 |