| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 17.09 | 20.4 | 13.94 |
| 2024 | 14 | 16.91 | 10.69 |
| 2023 | 15.72 | 19.84 | 12.6 |
| 2022 | 14.06 | 15.23 | 11.82 |
| 2021 | 14 | 18.57 | 10.36 |
| 2020 | 9.82 | 12.16 | 7.41 |
| 2019 | 9.74 | 10.96 | 9.03 |
| 2018 | 11.35 | 12.68 | 9.04 |
| 2017 | 12.15 | 14.68 | 10.88 |
| 2016 | 13.18 | 15.9 | 12.08 |
| 2015 | 15.04 | 21.25 | 11.31 |
| 2014 | 11.06 | 14.98 | 6.92 |
| 2013 | 11.02 | 16.15 | 8.3 |
| 2012 | 15.72 | 21.09 | 10.34 |
| 2011 | 24.25 | 29.96 | 19.26 |
| 2010 | 29.78 | 37.34 | 24.7 |
| 2009 | 21.97 | 31.24 | 15.75 |
| 2008 | 30.57 | 62.58 | 13.5 |
| 2007 | 45.98 | 58.5 | 37.43 |
| 2006 | 32.92 | 48.11 | 19.81 |
| 2005 | 9.41 | 21.17 | 5.94 |
| 2004 | 5.52 | 6.53 | 3.63 |
| 2003 | 4.77 | 5.66 | 3.46 |
| 2002 | 4.15 | 4.92 | 3.38 |
| 2001 | 5.8 | 9.82 | 2.93 |
| 2000 | 3.04 | 3.97 | 2.16 |
| 1999 | 3.13 | 4.97 | 2.39 |
| 1998 | 3.44 | 4.82 | 1.7 |