| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.47 | 1.8 | 1.39 |
| 2024 | 1.23 | 1.62 | 0.99 |
| 2023 | 1.39 | 1.65 | 1.15 |
| 2022 | 1.65 | 2.23 | 1.24 |
| 2021 | 3.19 | 8.16 | 0.87 |
| 2020 | 1.07 | 1.36 | 0.95 |
| 2019 | 1.46 | 2.07 | 1.13 |
| 2018 | 1.05 | 1.3 | 0.83 |
| 2017 | 1.6 | 1.92 | 1.23 |
| 2016 | 2.09 | 2.74 | 1.84 |
| 2015 | 2.99 | 4.48 | 2.13 |
| 2014 | 2.08 | 3.24 | 1.68 |
| 2013 | 2.2 | 3.31 | 1.64 |
| 2012 | 2.02 | 3.01 | 1.57 |
| 2011 | 2.96 | 3.81 | 2.3 |
| 2010 | 2.48 | 3.38 | 1.78 |
| 2009 | 1.86 | 2.45 | 0.93 |
| 2008 | 2 | 5.72 | 0.65 |
| 2007 | 3.67 | 5.48 | 1.69 |
| 2006 | 1.61 | 2.38 | 1.28 |
| 2005 | 1.42 | 2.06 | 0.88 |
| 2004 | 3.22 | 5.02 | 2.09 |
| 2003 | 4.48 | 5.23 | 3.85 |
| 2002 | 4.59 | 5.41 | 3.35 |
| 2001 | 5.89 | 7.38 | 4.38 |