| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.73 | 2.26 | 1.43 |
| 2024 | 1.49 | 1.8 | 1.23 |
| 2023 | 1.97 | 2.36 | 1.35 |
| 2022 | 2.56 | 3.53 | 1.74 |
| 2021 | 3.97 | 5.92 | 3.09 |
| 2020 | 2.66 | 4.27 | 1.76 |
| 2019 | 2.35 | 3.04 | 1.84 |
| 2018 | 3.16 | 4.52 | 2.38 |
| 2017 | 2.75 | 4.07 | 2.26 |
| 2016 | 2.94 | 5.33 | 2.08 |
| 2015 | 4.7 | 7.01 | 3.14 |
| 2014 | 2.13 | 3.65 | 1.65 |
| 2013 | 1.96 | 2.29 | 1.72 |
| 2012 | 2.38 | 3.43 | 1.7 |
| 2011 | 7.34 | 11.28 | 2.3 |
| 2010 | 6.52 | 8.33 | 4.93 |
| 2009 | 4.8 | 6.03 | 4.12 |
| 2008 | 7.51 | 13.55 | 3.38 |
| 2007 | 7.79 | 12.67 | 3.99 |
| 2006 | 3.56 | 4.59 | 2.84 |
| 2005 | 2.88 | 3.37 | 2.47 |
| 2004 | 4.58 | 8.16 | 2.57 |
| 2003 | 6.19 | 7.43 | 4.32 |
| 2002 | 4.46 | 5.2 | 3.2 |
| 2001 | 5.52 | 6.66 | 3.69 |
| 2000 | 5.58 | 7.54 | 3.53 |