| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.59 | 0.62 | 0.55 |
| 2024 | 0.62 | 0.79 | 0.49 |
| 2023 | 0.92 | 1.06 | 0.76 |
| 2022 | 1.18 | 1.59 | 0.88 |
| 2021 | 1.58 | 1.99 | 1.21 |
| 2020 | 2.2 | 2.94 | 1.77 |
| 2019 | 1.93 | 2.69 | 1.45 |
| 2018 | 2.26 | 3.06 | 1.77 |
| 2017 | 1.89 | 2.68 | 1.44 |
| 2016 | 1.61 | 1.93 | 1.37 |
| 2015 | 2.24 | 3.25 | 1.46 |
| 2014 | 1.88 | 2.43 | 1.59 |
| 2013 | 2.53 | 3.56 | 1.82 |
| 2012 | 3.16 | 3.77 | 2.66 |
| 2011 | 4.66 | 6.66 | 2.52 |
| 2010 | 3.31 | 5.02 | 2.36 |
| 2009 | 2.9 | 3.66 | 1.87 |
| 2008 | 3.81 | 8.28 | 1.29 |
| 2007 | 5.22 | 7.71 | 1.98 |
| 2006 | 1.67 | 2.14 | 1.36 |
| 2005 | 1.57 | 2.33 | 1.09 |
| 2004 | 3.13 | 4.5 | 2.05 |
| 2003 | 2.48 | 2.81 | 2.16 |
| 2002 | 3.68 | 4.5 | 3.08 |
| 2001 | 5.42 | 6.88 | 3.88 |
| 2000 | 5.27 | 7.09 | 3.96 |
| 1999 | 4.25 | 5.48 | 3.57 |
| 1998 | 4.56 | 5.61 | 2.97 |