| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.23 | 1.37 | 1.08 |
| 2024 | 1.21 | 1.48 | 0.97 |
| 2023 | 1.9 | 2.77 | 1.4 |
| 2022 | 2.11 | 2.88 | 1.52 |
| 2021 | 2.03 | 2.37 | 1.76 |
| 2020 | 2.43 | 3.39 | 1.85 |
| 2019 | 2.13 | 2.98 | 1.58 |
| 2018 | 3.41 | 5.81 | 2.08 |
| 2017 | 6.22 | 8.15 | 4.82 |
| 2016 | 5.52 | 8.09 | 4.11 |
| 2015 | 5.66 | 10.71 | 2.63 |
| 2014 | 2.63 | 4.08 | 2.14 |
| 2013 | 2.34 | 2.86 | 2.06 |
| 2012 | 2.62 | 3.3 | 1.92 |
| 2011 | 4.12 | 5.47 | 2.67 |
| 2010 | 4.03 | 5.24 | 3.14 |
| 2009 | 3.67 | 4.85 | 3.01 |
| 2008 | 3.82 | 7.44 | 1.94 |
| 2007 | 6.92 | 13.19 | 1.48 |
| 2006 | 1.54 | 1.94 | 1.25 |
| 2005 | 2.09 | 2.92 | 1.59 |
| 2004 | 3.28 | 5.13 | 2.2 |