| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.48 | 1.81 | 1.32 |
| 2024 | 1.38 | 1.66 | 1.23 |
| 2023 | 1.82 | 2.26 | 1.41 |
| 2022 | 2.75 | 3.65 | 1.95 |
| 2021 | 3.87 | 5.94 | 2.76 |
| 2020 | 3.33 | 5.92 | 2.15 |
| 2019 | 2.34 | 2.91 | 1.89 |
| 2018 | 3.52 | 4.61 | 2.09 |
| 2017 | 3.42 | 4.58 | 2.87 |
| 2016 | 2.62 | 2.99 | 2.28 |
| 2015 | 3.44 | 5.05 | 2.6 |
| 2014 | 2.91 | 3.64 | 2.59 |
| 2013 | 2.25 | 3.12 | 1.66 |
| 2012 | 1.98 | 2.3 | 1.56 |
| 2011 | 2.36 | 3.27 | 1.62 |
| 2010 | 3.86 | 4.94 | 3.1 |
| 2009 | 4.29 | 5.5 | 3.32 |
| 2008 | 4.17 | 6.69 | 2.15 |
| 2007 | 4.18 | 6.38 | 2.01 |
| 2006 | 1.94 | 2.84 | 1.52 |
| 2005 | 1.78 | 2.13 | 1.52 |
| 2004 | 2.45 | 4.28 | 1.06 |
| 2003 | 3.34 | 3.95 | 2.56 |
| 2002 | 3.73 | 4.15 | 2.91 |
| 2001 | 5.34 | 6.94 | 3.86 |
| 2000 | 10.69 | 12.18 | 7.6 |
| 1999 | 8.72 | 11.47 | 6.77 |