| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.54 | 0.57 | 0.5 |
| 2024 | 0.58 | 0.69 | 0.48 |
| 2023 | 0.73 | 1.13 | 0.61 |
| 2022 | 0.89 | 1.21 | 0.67 |
| 2021 | 2.32 | 5.49 | 0.73 |
| 2020 | 1.35 | 4.94 | 1.18 |
| 2019 | 1.61 | 2.59 | 1.28 |
| 2018 | 1.5 | 2.06 | 1.16 |
| 2017 | 1.98 | 2.64 | 1.7 |
| 2016 | 2.25 | 2.96 | 1.81 |
| 2015 | 2.89 | 5.39 | 1.84 |
| 2014 | 2.59 | 2.9 | 2.14 |
| 2013 | 2.94 | 3.36 | 2.63 |
| 2012 | 3.5 | 4.44 | 2.7 |
| 2011 | 5.91 | 8.07 | 3.48 |
| 2010 | 5.97 | 7.67 | 4.57 |
| 2009 | 6.04 | 8.09 | 3.57 |
| 2008 | 4.26 | 4.59 | 3.94 |
| 2007 | 6.68 | 9.16 | 4.56 |
| 2006 | 3.32 | 5.08 | 1.43 |
| 2005 | 1.22 | 2 | 0.66 |
| 2004 | 1.52 | 2.33 | 0.96 |
| 2003 | 2.3 | 2.98 | 1.65 |
| 2002 | 3.58 | 4.12 | 2.8 |
| 2001 | 5.57 | 7.41 | 3.63 |