| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.18 | 2.56 | 1.79 |
| 2024 | 1.14 | 1.98 | 0.87 |
| 2023 | 1.09 | 1.24 | 0.98 |
| 2022 | 1.14 | 1.44 | 0.94 |
| 2021 | 0.99 | 1.48 | 0.73 |
| 2020 | 0.74 | 1.06 | 0.65 |
| 2019 | 0.89 | 1.12 | 0.74 |
| 2018 | 0.98 | 1.45 | 0.72 |
| 2017 | 1.9 | 3.07 | 1.33 |
| 2016 | 2.36 | 3.52 | 1.74 |
| 2015 | 2.87 | 4.59 | 1.63 |
| 2014 | 1.67 | 3.24 | 1.26 |
| 2013 | 4.36 | 18.46 | 1.13 |
| 2012 | 5.17 | 16.46 | 2.71 |
| 2011 | 4.46 | 5.67 | 2.86 |
| 2010 | 4.78 | 5.72 | 3.45 |
| 2009 | 3.79 | 5.31 | 2.32 |
| 2008 | 4.18 | 8.46 | 1.8 |
| 2007 | 6.04 | 9.14 | 2.57 |
| 2006 | 2.19 | 2.8 | 1.72 |
| 2005 | 1.6 | 2.17 | 0.98 |
| 2004 | 2.6 | 3.3 | 1.88 |
| 2003 | 3.02 | 4.15 | 2.2 |
| 2002 | 4.44 | 5.16 | 3 |
| 2001 | 6.14 | 7.63 | 4.11 |
| 2000 | 5.65 | 7.64 | 3.79 |
| 1999 | 3.33 | 4.41 | 2.37 |
| 1998 | 3.16 | 3.75 | 1.65 |