| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.5 | 0.54 | 0.44 |
| 2024 | 0.43 | 0.76 | 0.33 |
| 2023 | 0.47 | 0.57 | 0.35 |
| 2022 | 0.46 | 0.54 | 0.4 |
| 2021 | 0.64 | 0.86 | 0.47 |
| 2020 | 0.96 | 1.13 | 0.83 |
| 2019 | 1.03 | 1.31 | 0.79 |
| 2018 | 1.04 | 1.5 | 0.76 |
| 2017 | 11.93 | 45.44 | 1.36 |
| 2016 | 4.63 | 5.63 | 3.11 |
| 2015 | 6.17 | 10.26 | 3.94 |
| 2014 | 5.52 | 7.48 | 3.26 |
| 2013 | 3.81 | 4.73 | 2.42 |
| 2012 | 3.65 | 4.56 | 2.64 |
| 2011 | 4.84 | 6.7 | 2.76 |
| 2010 | 4.25 | 7.21 | 2.75 |
| 2009 | 3.06 | 4.23 | 1.54 |
| 2008 | 2.66 | 5.7 | 1.11 |
| 2007 | 4.4 | 9.99 | 1.25 |
| 2006 | 1.06 | 1.4 | 0.76 |
| 2005 | 0.87 | 1.27 | 0.59 |
| 2004 | 1.56 | 2.06 | 1.25 |
| 2003 | 1.88 | 2.44 | 1.51 |
| 2002 | 3.16 | 3.53 | 2.91 |