| Table 2. Estimated stock numbers. | ||||||
| Year\Age | 0 | 1 | 2 | 3 | 4 | 5+ | 
| 1991 | 215561 | 205048 | 151600 | 69425 | 25286 | 72766 | 
| 1992 | 173685 | 152818 | 131268 | 97052 | 44534 | 69843 | 
| 1993 | 200386 | 124617 | 93807 | 80338 | 62131 | 78826 | 
| 1994 | 208355 | 143200 | 78120 | 57584 | 50262 | 94561 | 
| 1995 | 212990 | 147267 | 87641 | 48728 | 36098 | 95990 | 
| 1996 | 194658 | 154508 | 90672 | 54448 | 32112 | 90129 | 
| 1997 | 194658 | 139386 | 93340 | 56162 | 35313 | 83366 | 
| 1998 | 191760 | 135808 | 85221 | 56106 | 35102 | 80017 | 
| 1999 | 262236 | 139944 | 86336 | 55050 | 36680 | 82043 | 
| 2000 | 298642 | 198194 | 91126 | 56613 | 37049 | 86509 | 
| 2001 | 405550 | 215993 | 126500 | 58924 | 38025 | 89859 | 
| 2002 | 517104 | 305285 | 137173 | 79937 | 39815 | 93995 | 
| 2003 | 609260 | 381551 | 194269 | 86942 | 52575 | 96568 | 
| 2004 | 427624 | 467428 | 241832 | 122639 | 58454 | 110084 | 
| 2005 | 395933 | 304980 | 304066 | 148301 | 80419 | 118539 | 
| 2006 | 406362 | 298343 | 195830 | 194075 | 99012 | 143774 | 
| 2007 | 417483 | 294196 | 188905 | 123624 | 128284 | 168384 | 
| 2008 | 485046 | 305285 | 186279 | 119731 | 83117 | 204434 | 
| 2009 | 583617 | 357182 | 192914 | 119491 | 80580 | 202400 | 
| 2010 | 636029 | 431490 | 222793 | 121783 | 80017 | 197996 | 
| 2011 | 675359 | 476394 | 271848 | 140927 | 80902 | 195048 | 
| 2012 | 623435 | 515555 | 308353 | 175431 | 94183 | 198392 | 
| 2013 | 788589 | 460469 | 335038 | 202805 | 119253 | 213844 | 
| 2014 | 747882 | 601391 | 294785 | 217510 | 137585 | 240867 |