| Table 2. Estimated stock numbers. | ||||||||
| Year\Age | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8+ | 
| 2000 | 20494 | 15245 | 11082 | 8907 | 2733 | 933 | 195 | 799 | 
| 2001 | 33725 | 16904 | 12133 | 7043 | 2729 | 546 | 309 | 398 | 
| 2002 | 34683 | 27146 | 13386 | 7538 | 2080 | 508 | 181 | 274 | 
| 2003 | 34441 | 28396 | 21390 | 8463 | 2320 | 406 | 179 | 164 | 
| 2004 | 33024 | 28085 | 22629 | 13382 | 2658 | 553 | 158 | 118 | 
| 2005 | 30061 | 26689 | 22226 | 14199 | 4321 | 671 | 227 | 87 | 
| 2006 | 28085 | 24441 | 20682 | 13501 | 4945 | 1163 | 264 | 89 | 
| 2007 | 28170 | 22834 | 19080 | 12324 | 4843 | 1458 | 464 | 92 | 
| 2008 | 28567 | 23179 | 17724 | 11501 | 4329 | 1397 | 597 | 118 | 
| 2009 | 33658 | 23365 | 18124 | 10601 | 4378 | 1179 | 552 | 134 | 
| 2010 | 30853 | 27917 | 18361 | 11153 | 4359 | 1358 | 457 | 162 | 
| 2011 | 33256 | 25210 | 22049 | 11449 | 5063 | 1597 | 546 | 197 | 
| 2012 | 24612 | 27282 | 19452 | 13698 | 5315 | 2051 | 665 | 262 |