| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.26 | 1.43 | 1.15 |
| 2024 | 1.37 | 1.6 | 1.13 |
| 2023 | 1.78 | 2 | 1.44 |
| 2022 | 2.16 | 3.27 | 1.69 |
| 2021 | 3.09 | 4.19 | 2.45 |
| 2020 | 3.24 | 4.83 | 2.23 |
| 2019 | 2.31 | 2.83 | 1.85 |
| 2018 | 2.46 | 3.81 | 1.69 |
| 2017 | 3.18 | 3.86 | 2.72 |
| 2016 | 3.68 | 5.34 | 3 |
| 2015 | 5.3 | 7.7 | 4.04 |
| 2014 | 4.89 | 6.63 | 4.01 |
| 2013 | 5.16 | 7.89 | 2.9 |
| 2012 | 3.79 | 4.74 | 2.64 |
| 2011 | 4.22 | 5.09 | 3.42 |
| 2010 | 4.65 | 5.69 | 3.47 |
| 2009 | 3.56 | 4.78 | 2.13 |
| 2008 | 3.49 | 6.57 | 1.52 |
| 2007 | 5.23 | 7.76 | 3.11 |
| 2006 | 3.17 | 3.98 | 2.21 |
| 2005 | 2.53 | 3.65 | 1.79 |
| 2004 | 4.41 | 5.96 | 2.62 |
| 2003 | 5.46 | 6.62 | 4.2 |