| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.76 | 3.44 | 2.37 |
| 2024 | 2.58 | 3.68 | 1.99 |
| 2023 | 3.1 | 4.92 | 2.19 |
| 2022 | 2.99 | 3.87 | 1.98 |
| 2021 | 2.51 | 3.89 | 1.95 |
| 2020 | 1.89 | 2.39 | 1.54 |
| 2019 | 1.64 | 2.25 | 1.12 |
| 2018 | 1.71 | 2.65 | 1.02 |
| 2017 | 2.67 | 3.26 | 2.17 |
| 2016 | 3.11 | 4.42 | 2.49 |
| 2015 | 4.62 | 7.95 | 2.59 |
| 2014 | 3.44 | 4.08 | 2.51 |
| 2013 | 6.09 | 11.11 | 2.58 |
| 2012 | 6.5 | 8.61 | 5.13 |
| 2011 | 10.29 | 12.93 | 7.32 |
| 2010 | 14.08 | 21.04 | 8.46 |
| 2009 | 6.26 | 10.84 | 2.44 |
| 2008 | 4.53 | 9 | 1.92 |
| 2007 | 7.4 | 12.59 | 1.83 |
| 2006 | 1.81 | 2.69 | 1.1 |
| 2005 | 1.43 | 2.22 | 0.93 |
| 2004 | 2.59 | 3.48 | 2.03 |
| 2003 | 2.88 | 4.02 | 2.13 |