| Table 2. Estimated stock numbers. | ||||||||
| Year\Age | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9+ |
| 1984 | 3132 | 1792 | 561 | 378 | 119 | 85 | 119 | 488 |
| 1985 | 5041 | 2688 | 924 | 261 | 237 | 87 | 41 | 320 |
| 1986 | 4347 | 4637 | 1987 | 671 | 167 | 146 | 86 | 241 |
| 1987 | 4275 | 3596 | 3117 | 1161 | 420 | 143 | 92 | 231 |
| 1988 | 3958 | 3873 | 2723 | 1781 | 501 | 167 | 79 | 191 |
| 1989 | 5589 | 2574 | 2617 | 1743 | 1171 | 259 | 98 | 161 |
| 1990 | 7252 | 4679 | 1792 | 1663 | 1040 | 679 | 127 | 137 |
| 1991 | 6860 | 5581 | 2945 | 1065 | 963 | 720 | 494 | 196 |
| 1992 | 7940 | 5400 | 3322 | 1549 | 620 | 490 | 385 | 454 |
| 1993 | 5942 | 6951 | 3647 | 2103 | 899 | 286 | 267 | 358 |
| 1994 | 3072 | 5178 | 5007 | 2209 | 1217 | 403 | 137 | 236 |
| 1995 | 3482 | 2662 | 4156 | 3325 | 1490 | 824 | 289 | 264 |
| 1996 | 2198 | 3358 | 1895 | 2461 | 1660 | 827 | 429 | 450 |
| 1997 | 1315 | 1374 | 1807 | 1306 | 1624 | 1169 | 719 | 648 |
| 1998 | 3530 | 856 | 873 | 1000 | 803 | 877 | 724 | 857 |
| 1999 | 3567 | 4118 | 641 | 758 | 647 | 571 | 556 | 922 |
| 2000 | 2827 | 2637 | 2759 | 435 | 510 | 404 | 436 | 1079 |
| 2001 | 4199 | 2328 | 1950 | 1647 | 312 | 418 | 211 | 1100 |
| 2002 | 6018 | 4216 | 1535 | 1605 | 1345 | 275 | 328 | 1229 |
| 2003 | 3884 | 4330 | 2984 | 1245 | 1225 | 736 | 132 | 904 |
| 2004 | 4387 | 3886 | 3465 | 1840 | 858 | 663 | 392 | 627 |
| 2005 | 3146 | 4970 | 3945 | 2359 | 994 | 407 | 329 | 485 |
| 2006 | 2563 | 2349 | 3681 | 2492 | 1596 | 603 | 279 | 533 |
| 2007 | 2557 | 1931 | 1579 | 2183 | 1148 | 815 | 413 | 588 |
| 2008 | 2869 | 1701 | 1336 | 1085 | 1438 | 782 | 732 | 831 |
| 2009 | 2491 | 2585 | 1246 | 953 | 678 | 852 | 380 | 916 |
| 2010 | 2146 | 2233 | 1583 | 690 | 618 | 436 | 744 | 970 |
| 2011 | 1854 | 2068 | 1647 | 1002 | 404 | 377 | 241 | 1293 |
| 2012 | 1429 | 1291 | 1398 | 963 | 655 | 276 | 366 | 1267 |
| 2013 | 1415 | 1287 | 1087 | 1034 | 737 | 478 | 195 | 882 |
| 2014 | 1378 | 1277 | 916 | 704 | 817 | 579 | 396 | 627 |