| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.1 | 2.66 | 1.85 |
| 2024 | 1.96 | 2.41 | 1.57 |
| 2023 | 2.68 | 3.53 | 2.12 |
| 2022 | 3.93 | 5.74 | 3.17 |
| 2021 | 4.43 | 6.79 | 2.9 |
| 2020 | 3.39 | 5.76 | 2.61 |
| 2019 | 2.69 | 3.34 | 1.85 |
| 2018 | 2.14 | 3.05 | 1.57 |
| 2017 | 2.75 | 3.47 | 2.18 |
| 2016 | 2.29 | 2.86 | 1.7 |
| 2015 | 2.4 | 3.58 | 1.48 |
| 2014 | 1.8 | 2.44 | 1.33 |
| 2013 | 1.73 | 2.3 | 1.39 |
| 2012 | 2.24 | 2.92 | 1.72 |
| 2011 | 3.22 | 3.96 | 2.09 |
| 2010 | 2.9 | 4.45 | 2.03 |
| 2009 | 2.45 | 3.42 | 1.37 |
| 2008 | 5.03 | 14.28 | 1.03 |
| 2007 | 10.72 | 18.05 | 6.8 |
| 2006 | 7.67 | 13.66 | 3.54 |
| 2005 | 3.06 | 4.5 | 2.11 |
| 2004 | 2.97 | 4.19 | 2.11 |
| 2003 | 3.89 | 4.61 | 2.77 |