| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.96 | 1.04 | 0.87 |
| 2024 | 0.87 | 1.19 | 0.71 |
| 2023 | 0.9 | 1.02 | 0.83 |
| 2022 | 0.92 | 1.14 | 0.76 |
| 2021 | 1.17 | 1.57 | 1 |
| 2020 | 1.31 | 1.69 | 1.04 |
| 2019 | 1.22 | 1.56 | 0.95 |
| 2018 | 1.15 | 1.89 | 0.75 |
| 2017 | 1.9 | 2.12 | 1.5 |
| 2016 | 1.88 | 2.47 | 1.53 |
| 2015 | 3.09 | 4.43 | 1.55 |
| 2014 | 1.57 | 3.67 | 1.07 |
| 2013 | 1.28 | 1.63 | 1.03 |
| 2012 | 1.39 | 1.6 | 1.11 |
| 2011 | 1.45 | 1.76 | 1.13 |
| 2010 | 2.78 | 8.19 | 1.57 |
| 2009 | 5.84 | 8.15 | 3.4 |
| 2008 | 18.95 | 225.2 | 2.97 |
| 2007 | 38.64 | 194.82 | 1.84 |
| 2006 | 2.76 | 5.29 | 0.98 |
| 2005 | 1.16 | 1.76 | 0.61 |
| 2004 | 2.14 | 2.82 | 1.76 |
| 2003 | 2.14 | 2.73 | 1.85 |
| 2002 | 2.54 | 3.19 | 1.33 |
| 2001 | 3.13 | 3.99 | 2.12 |
| 2000 | 3.05 | 4.09 | 1.83 |
| 1999 | 1.96 | 2.52 | 1.6 |
| 1998 | 2.53 | 3.12 | 1.91 |