| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.97 | 9.21 | 3.53 |
| 2024 | 3.91 | 5.46 | 3.04 |
| 2023 | 5.16 | 6.16 | 4.58 |
| 2022 | 5.41 | 8.68 | 4.08 |
| 2021 | 4.44 | 5.28 | 3.7 |
| 2020 | 6.08 | 7.96 | 4.65 |
| 2019 | 9.29 | 13.74 | 7.06 |
| 2018 | 11.66 | 19.59 | 7.12 |
| 2017 | 18.97 | 33.82 | 9.25 |
| 2016 | 10.32 | 13.84 | 5.67 |
| 2015 | 6.83 | 11.46 | 3.6 |
| 2014 | 3.38 | 4.23 | 2.45 |
| 2013 | 2.8 | 3.66 | 2.19 |
| 2012 | 4.01 | 5.4 | 2.39 |
| 2011 | 15.12 | 40.2 | 3.7 |
| 2010 | 20.69 | 40.87 | 9.85 |
| 2009 | 19.15 | 39.64 | 5.41 |
| 2008 | 6.08 | 8.61 | 3.2 |
| 2007 | 3.69 | 6.27 | 1.68 |
| 2006 | 1.38 | 1.87 | 0.95 |
| 2005 | 0.94 | 1.25 | 0.65 |
| 2004 | 1.6 | 2.16 | 1.09 |
| 2003 | 2 | 2.63 | 1.5 |
| 2002 | 3.2 | 3.77 | 2.42 |
| 2001 | 4.08 | 5 | 2.98 |
| 2000 | 4.77 | 5.96 | 3.49 |
| 1999 | 3.75 | 4.65 | 2.91 |