| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.85 | 3.63 | 1.99 |
| 2024 | 3.02 | 5.75 | 2 |
| 2023 | 3.53 | 4.5 | 2.98 |
| 2022 | 3.05 | 4.19 | 2.42 |
| 2021 | 2.92 | 3.71 | 2.4 |
| 2020 | 3.43 | 4.49 | 2.76 |
| 2019 | 3.4 | 4.49 | 2.85 |
| 2018 | 4.12 | 6.13 | 2.39 |
| 2017 | 5.41 | 7.8 | 4.01 |
| 2016 | 7.04 | 8.75 | 5.1 |
| 2015 | 7.65 | 15.33 | 4.42 |
| 2014 | 4.5 | 5.78 | 3.27 |
| 2013 | 3.35 | 4.39 | 2.69 |
| 2012 | 3.55 | 4.17 | 2.98 |
| 2011 | 5.29 | 7.02 | 2.99 |
| 2010 | 6.33 | 7.98 | 5.12 |
| 2009 | 5.35 | 7.37 | 2.59 |
| 2008 | 3.74 | 5.99 | 1.85 |
| 2007 | 3.58 | 5.34 | 1.95 |
| 2006 | 1.39 | 2.21 | 0.7 |
| 2005 | 0.96 | 1.5 | 0.4 |
| 2004 | 2.07 | 3.28 | 1.31 |
| 2003 | 2.86 | 4.12 | 2 |
| 2002 | 4.01 | 4.51 | 3.56 |
| 2001 | 5.1 | 6.4 | 3.46 |