| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.75 | 1.83 | 1.6 |
| 2024 | 1.77 | 2.11 | 1.45 |
| 2023 | 1.72 | 2.12 | 1.38 |
| 2022 | 1.42 | 1.92 | 1.15 |
| 2021 | 1.7 | 2.05 | 1.52 |
| 2020 | 2.17 | 2.61 | 1.85 |
| 2019 | 2.54 | 3.6 | 2.01 |
| 2018 | 4.19 | 5.68 | 2.75 |
| 2017 | 5.09 | 5.58 | 4.49 |
| 2016 | 5.43 | 6.33 | 4.78 |
| 2015 | 7.78 | 11.43 | 5.05 |
| 2014 | 10.26 | 13.3 | 8.88 |
| 2013 | 10.61 | 14.14 | 6.89 |
| 2012 | 6.24 | 7.63 | 5.04 |
| 2011 | 6.89 | 9.85 | 5.53 |
| 2010 | 7.49 | 10.14 | 5.7 |
| 2009 | 4.55 | 6.34 | 3.31 |
| 2008 | 3.94 | 6.45 | 2.66 |
| 2007 | 5.52 | 7.1 | 3.34 |
| 2006 | 3.01 | 4.05 | 2.07 |
| 2005 | 3.06 | 3.45 | 2.28 |
| 2004 | 2.92 | 3.77 | 2.31 |
| 2003 | 3.47 | 4.59 | 2.63 |