| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.54 | 2.69 | 2.37 |
| 2024 | 2.6 | 2.95 | 2.18 |
| 2023 | 3.31 | 4.29 | 2.77 |
| 2022 | 4.73 | 6.54 | 3.85 |
| 2021 | 4.7 | 8.37 | 3.64 |
| 2020 | 4.46 | 5.72 | 3.23 |
| 2019 | 4.76 | 6.4 | 3.95 |
| 2018 | 6.11 | 9.25 | 4.69 |
| 2017 | 9.53 | 16.4 | 6.1 |
| 2016 | 3.79 | 6.88 | 2.4 |
| 2015 | 2.57 | 4.47 | 1.58 |
| 2014 | 2.04 | 2.61 | 1.7 |
| 2013 | 1.74 | 2.52 | 1.22 |
| 2012 | 2 | 2.73 | 1.25 |
| 2011 | 3.4 | 4.47 | 2.07 |
| 2010 | 2.81 | 3.78 | 1.95 |
| 2009 | 2.35 | 4.01 | 1.06 |
| 2008 | 2.58 | 4.85 | 0.74 |
| 2007 | 2.17 | 4.25 | 0.73 |
| 2006 | 0.72 | 0.89 | 0.63 |
| 2005 | 1.14 | 1.78 | 0.58 |
| 2004 | 2.22 | 3.7 | 1.7 |