| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.88 | 0.97 | 0.8 |
| 2024 | 0.92 | 1.14 | 0.73 |
| 2023 | 1.22 | 1.68 | 0.91 |
| 2022 | 2.16 | 2.94 | 1.5 |
| 2021 | 2.5 | 5.32 | 1.44 |
| 2020 | 1.18 | 2.29 | 0.98 |
| 2019 | 1.36 | 2.13 | 1.09 |
| 2018 | 2.13 | 2.92 | 1.35 |
| 2017 | 1.64 | 2.18 | 1.18 |
| 2016 | 1.4 | 1.89 | 1.1 |
| 2015 | 1.81 | 3.3 | 1.05 |
| 2014 | 1.6 | 2.16 | 1.28 |
| 2013 | 2.03 | 2.77 | 1.26 |
| 2012 | 1.3 | 1.65 | 1.03 |
| 2011 | 1.93 | 2.66 | 1.08 |
| 2010 | 2.67 | 4.02 | 1.6 |
| 2009 | 3.99 | 5.02 | 3.29 |
| 2008 | 9.51 | 19.37 | 2.65 |
| 2007 | 10.19 | 15.84 | 5.9 |
| 2006 | 3.87 | 5.99 | 2.89 |
| 2005 | 2.87 | 3.48 | 2.28 |
| 2004 | 2.62 | 3.19 | 1.51 |
| 2003 | 2.43 | 3.04 | 1.77 |
| 2002 | 3.54 | 4.17 | 2.57 |