| 年度 | 应规(百分比) | 自愿(百分比) | 总计 |
| 2009 | 287 (73%) | 105 (27%) | 392 |
| 2010 | 279 (73%) | 103 (27%) | 382 |
| 2011 | 319 (66%) | 162 (34%) | 481 |
| 2012 | 334 (60%) | 221 (40%) | 555 |
| 2013 | 349 (58%) | 248 (42%) | 597 |
| 2014 | 364 (58%) | 267 (42%) | 631 |
| 2015 | 311 (57%) | 231 (43%) | 542 |
| 总计 | 2243 | 1337 | 3580 |