| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.38 | 1.58 | 1.21 |
| 2024 | 1.62 | 2.41 | 1.2 |
| 2023 | 2.71 | 3.99 | 1.78 |
| 2022 | 3.83 | 5.46 | 2.53 |
| 2021 | 4.88 | 6.47 | 3.23 |
| 2020 | 4.54 | 5.59 | 3.38 |
| 2019 | 3.86 | 4.96 | 2.65 |
| 2018 | 4.33 | 6.78 | 2.9 |
| 2017 | 8.63 | 10.17 | 6.08 |
| 2016 | 8.67 | 12.03 | 7.61 |
| 2015 | 11.9 | 16.74 | 8.3 |
| 2014 | 14.4 | 23.68 | 9.37 |
| 2013 | 19.61 | 24.52 | 13.43 |
| 2012 | 12.93 | 16.42 | 9.68 |
| 2011 | 16.28 | 24.75 | 10.87 |
| 2010 | 23.65 | 35.37 | 11.48 |
| 2009 | 9.9 | 15 | 6.04 |
| 2008 | 7.54 | 13.24 | 3.73 |
| 2007 | 8.62 | 11.89 | 4.67 |
| 2006 | 5.34 | 6.97 | 4.43 |
| 2005 | 6.08 | 7.19 | 5.16 |
| 2004 | 8.98 | 11.96 | 5.55 |
| 2003 | 7.43 | 9.35 | 5.6 |
| 2002 | 9.67 | 13.3 | 5.08 |
| 2001 | 10.66 | 13.56 | 6.94 |
| 2000 | 8.96 | 11.87 | 5.19 |
| 1999 | 5.33 | 7.37 | 3.75 |
| 1998 | 4.74 | 6.41 | 3.45 |
| 1997 | 4.55 | 7.11 | 2.8 |