| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.06 | 1.76 | 0.73 |
| 2024 | 0.87 | 1.3 | 0.55 |
| 2023 | 1.06 | 1.26 | 0.89 |
| 2022 | 1.14 | 1.5 | 0.9 |
| 2021 | 1.74 | 2.44 | 1.19 |
| 2020 | 1.93 | 2.52 | 1.51 |
| 2019 | 1.68 | 2.45 | 1.35 |
| 2018 | 1.89 | 2.33 | 1.43 |
| 2017 | 2.72 | 3.96 | 2.04 |
| 2016 | 2.84 | 3.32 | 2.34 |
| 2015 | 3.31 | 5.13 | 2.26 |
| 2014 | 1.67 | 2.56 | 1.32 |
| 2013 | 1.58 | 1.95 | 1.32 |
| 2012 | 1.73 | 2.43 | 1.15 |
| 2011 | 3.45 | 5.15 | 2.23 |
| 2010 | 3.61 | 5.63 | 2.42 |
| 2009 | 2.46 | 3.53 | 1.41 |
| 2008 | 3.21 | 9.56 | 1.02 |
| 2007 | 5.97 | 9.13 | 3.11 |
| 2006 | 1.99 | 3 | 1.16 |
| 2005 | 1.59 | 1.94 | 1.2 |
| 2004 | 1.71 | 2.62 | 0.88 |
| 2003 | 2.04 | 2.61 | 1.62 |
| 2002 | 3.17 | 3.54 | 2.74 |
| 2001 | 4.34 | 5.16 | 3.23 |