| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.59 | 2 | 1.3 |
| 2024 | 1.52 | 2.08 | 0.97 |
| 2023 | 1.5 | 2.1 | 1.28 |
| 2022 | 1.4 | 1.81 | 0.99 |
| 2021 | 0.85 | 1.41 | 0.68 |
| 2020 | 0.94 | 1.06 | 0.86 |
| 2019 | 1.04 | 1.39 | 0.92 |
| 2018 | 1.05 | 1.31 | 0.89 |
| 2017 | 1.64 | 2.3 | 1.19 |
| 2016 | 2.1 | 3.19 | 1.85 |
| 2015 | 2.86 | 4.67 | 1.76 |
| 2014 | 1.57 | 1.96 | 1.34 |
| 2013 | 1.61 | 1.87 | 1.38 |
| 2012 | 2.04 | 2.93 | 1.53 |
| 2011 | 2.56 | 3.15 | 1.71 |
| 2010 | 3.29 | 4.31 | 2.7 |
| 2009 | 2.46 | 3.08 | 1.72 |
| 2008 | 2.69 | 4.78 | 1.21 |
| 2007 | 3.91 | 6.33 | 1.35 |
| 2006 | 1.17 | 1.42 | 1.01 |
| 2005 | 1.43 | 2 | 0.91 |
| 2004 | 2.01 | 2.82 | 1.59 |
| 2003 | 2.26 | 2.92 | 1.69 |
| 2002 | 3.54 | 4.04 | 3.16 |
| 2001 | 4.62 | 5.52 | 3.16 |
| 2000 | 5.05 | 6.12 | 3.55 |
| 1999 | 3.45 | 4.42 | 2.78 |
| 1998 | 4.01 | 4.74 | 3.24 |