| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.8 | 2.39 | 1.47 |
| 2024 | 1.18 | 2.17 | 0.64 |
| 2023 | 1.25 | 1.42 | 1.06 |
| 2022 | 1.55 | 2.88 | 1.06 |
| 2021 | 2.33 | 4.85 | 1.78 |
| 2020 | 1.8 | 2.39 | 1.39 |
| 2019 | 1.8 | 2.36 | 1.53 |
| 2018 | 2.36 | 4.09 | 1.54 |
| 2017 | 3.47 | 4.18 | 2.91 |
| 2016 | 3.38 | 4.6 | 2.43 |
| 2015 | 3.43 | 6.1 | 2.27 |
| 2014 | 2.79 | 3.33 | 2.37 |
| 2013 | 3.46 | 4.34 | 3.01 |
| 2012 | 3.26 | 4.99 | 2.54 |
| 2011 | 3.67 | 4.83 | 2.61 |
| 2010 | 4.14 | 5.38 | 3.16 |
| 2009 | 3.96 | 5.7 | 2.34 |
| 2008 | 3.38 | 5.76 | 1.51 |
| 2007 | 3.95 | 5.05 | 2.01 |
| 2006 | 1.97 | 2.33 | 1.76 |
| 2005 | 1.96 | 2.62 | 1.24 |
| 2004 | 2.95 | 3.68 | 2.44 |
| 2003 | 3.22 | 3.82 | 2.41 |
| 2002 | 4.07 | 4.65 | 2.92 |
| 2001 | 4.48 | 5.88 | 3.75 |
| 2000 | 3.94 | 4.78 | 3.03 |
| 1999 | 3.11 | 3.82 | 2.62 |
| 1998 | 3.04 | 3.61 | 2.45 |
| 1997 | 3.12 | 4.54 | 2.17 |