| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.08 | 3.72 | 2.57 |
| 2024 | 1.85 | 3.73 | 1.43 |
| 2023 | 2.28 | 2.71 | 1.71 |
| 2022 | 1.77 | 2.19 | 1.13 |
| 2021 | 1.13 | 1.61 | 0.74 |
| 2020 | 0.77 | 0.88 | 0.56 |
| 2019 | 0.8 | 0.88 | 0.73 |
| 2018 | 1 | 1.2 | 0.79 |
| 2017 | 1.26 | 1.48 | 1.02 |
| 2016 | 1.42 | 1.82 | 1.14 |
| 2015 | 1.51 | 2.51 | 1.02 |
| 2014 | 0.97 | 1.13 | 0.85 |
| 2013 | 1.18 | 1.5 | 0.97 |
| 2012 | 1.12 | 1.33 | 0.87 |
| 2011 | 1.57 | 2.47 | 1.01 |
| 2010 | 1.63 | 2.19 | 1.28 |
| 2009 | 1.42 | 1.75 | 1.15 |
| 2008 | 1.49 | 2.87 | 0.92 |
| 2007 | 2.56 | 4.12 | 1.13 |
| 2006 | 0.99 | 1.31 | 0.76 |
| 2005 | 0.4 | 0.76 | 0.25 |
| 2004 | 0.44 | 0.61 | 0.31 |
| 2003 | 0.48 | 0.6 | 0.43 |
| 2002 | 0.57 | 0.68 | 0.42 |
| 2001 | 0.78 | 1.32 | 0.27 |
| 2000 | 0.24 | 0.31 | 0.2 |
| 1999 | 0.2 | 0.37 | 0.11 |
| 1998 | 0.26 | 0.43 | 0.13 |