| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.27 | 2.7 | 2.05 |
| 2024 | 1.79 | 2.58 | 1.31 |
| 2023 | 1.79 | 2.12 | 1.62 |
| 2022 | 1.77 | 2.07 | 1.53 |
| 2021 | 2.01 | 2.64 | 1.79 |
| 2020 | 2.76 | 4.88 | 2.09 |
| 2019 | 2.01 | 2.74 | 1.55 |
| 2018 | 2.62 | 3.86 | 1.74 |
| 2017 | 2.69 | 3.43 | 2.26 |
| 2016 | 3.08 | 4 | 2.6 |
| 2015 | 4.64 | 10.07 | 2.75 |
| 2014 | 2.52 | 4.25 | 1.78 |
| 2013 | 1.82 | 2.23 | 1.47 |
| 2012 | 1.69 | 2.1 | 1.3 |
| 2011 | 2.67 | 3.65 | 1.63 |
| 2010 | 3.07 | 4.07 | 2.32 |
| 2009 | 2.12 | 2.77 | 1.38 |
| 2008 | 2.09 | 3.59 | 1.02 |
| 2007 | 2.4 | 3.92 | 1.14 |
| 2006 | 0.99 | 1.32 | 0.72 |
| 2005 | 0.74 | 0.88 | 0.58 |
| 2004 | 1.3 | 2.26 | 0.76 |
| 2003 | 1.95 | 2.6 | 1.28 |
| 2002 | 2.52 | 2.82 | 1.92 |
| 2001 | 3.1 | 3.7 | 2.42 |
| 2000 | 2.95 | 3.55 | 2.12 |
| 1999 | 2.14 | 2.75 | 1.76 |
| 1998 | 2.69 | 3.22 | 2.05 |