| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.11 | 1.18 | 1 |
| 2024 | 1.04 | 1.55 | 0.82 |
| 2023 | 1.22 | 1.41 | 1.04 |
| 2022 | 1.21 | 1.45 | 1.04 |
| 2021 | 1.45 | 1.74 | 1.18 |
| 2020 | 1.86 | 3.16 | 1.26 |
| 2019 | 1.65 | 2.4 | 1.33 |
| 2018 | 1.53 | 1.99 | 1.05 |
| 2017 | 2.17 | 2.88 | 1.71 |
| 2016 | 4.03 | 17.67 | 2.14 |
| 2015 | 4.25 | 7.49 | 2.53 |
| 2014 | 1.72 | 3.96 | 1.48 |
| 2013 | 1.83 | 2.4 | 1.43 |
| 2012 | 2.74 | 3.91 | 1.86 |
| 2011 | 5.04 | 6.75 | 3.39 |
| 2010 | 7.07 | 8.45 | 5.64 |
| 2009 | 5.53 | 8.47 | 3.52 |
| 2008 | 6.13 | 10.35 | 2.89 |
| 2007 | 8.42 | 11.14 | 4.83 |
| 2006 | 3.06 | 5.11 | 1.85 |
| 2005 | 1.98 | 2.71 | 1.4 |
| 2004 | 2.01 | 2.51 | 1.72 |
| 2003 | 2.5 | 3.26 | 1.84 |
| 2002 | 3.97 | 4.51 | 3.12 |
| 2001 | 5.14 | 6.09 | 3.68 |