| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.24 | 1.39 | 1.07 |
| 2024 | 1.17 | 1.49 | 0.79 |
| 2023 | 1.35 | 1.56 | 1.2 |
| 2022 | 1.22 | 1.5 | 0.79 |
| 2021 | 0.89 | 1.33 | 0.59 |
| 2020 | 0.92 | 1.27 | 0.72 |
| 2019 | 1.18 | 1.92 | 0.93 |
| 2018 | 1.31 | 1.73 | 0.93 |
| 2017 | 2.17 | 2.89 | 1.5 |
| 2016 | 3.16 | 4.12 | 2.54 |
| 2015 | 3.59 | 6.39 | 2.22 |
| 2014 | 2.36 | 4 | 1.51 |
| 2013 | 1.71 | 2.08 | 1.38 |
| 2012 | 1.67 | 2.24 | 1.24 |
| 2011 | 1.84 | 2.31 | 1.35 |
| 2010 | 2.88 | 4.92 | 2.04 |
| 2009 | 4.93 | 7.45 | 2.23 |
| 2008 | 4.61 | 9.76 | 1.71 |
| 2007 | 9.16 | 15.14 | 2.22 |
| 2006 | 1.35 | 2.32 | 0.83 |
| 2005 | 0.92 | 1.17 | 0.78 |
| 2004 | 1.37 | 2.06 | 0.98 |
| 2003 | 1.63 | 2.37 | 1.37 |
| 2002 | 3.87 | 6.06 | 2.58 |
| 2001 | 6.43 | 7.53 | 5.08 |
| 2000 | 7.37 | 9.55 | 5.68 |
| 1999 | 5.22 | 8.15 | 3.67 |
| 1998 | 4.74 | 6 | 3.65 |