| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.18 | 1.4 | 1.07 |
| 2024 | 1.18 | 1.58 | 0.96 |
| 2023 | 1.54 | 1.92 | 1.29 |
| 2022 | 1.65 | 1.87 | 1.41 |
| 2021 | 1.77 | 2.28 | 1.49 |
| 2020 | 2.56 | 5.24 | 1.97 |
| 2019 | 1.97 | 2.76 | 1.64 |
| 2018 | 2.82 | 4.27 | 1.8 |
| 2017 | 5.08 | 6.14 | 3.97 |
| 2016 | 5.35 | 6.42 | 4.17 |
| 2015 | 5.69 | 10.49 | 3.44 |
| 2014 | 3.29 | 4.62 | 2.29 |
| 2013 | 4.47 | 6.31 | 2.85 |
| 2012 | 4.43 | 5.19 | 3.49 |
| 2011 | 6.4 | 9.03 | 4.04 |
| 2010 | 6.14 | 10.74 | 3.56 |
| 2009 | 4.21 | 5.67 | 2.64 |
| 2008 | 3.48 | 5.64 | 1.92 |
| 2007 | 4.34 | 6.13 | 2.71 |
| 2006 | 2.72 | 3.1 | 2.11 |
| 2005 | 2.52 | 3.24 | 1.79 |
| 2004 | 3.69 | 5.55 | 2.42 |