| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 8.6 | 9.95 | 7.74 |
| 2024 | 5.35 | 14.32 | 2.83 |
| 2023 | 4.47 | 6.44 | 2.95 |
| 2022 | 5.81 | 12.59 | 0.95 |
| 2021 | 0.74 | 1.27 | 0.46 |
| 2020 | 1.05 | 1.39 | 0.74 |
| 2019 | 1.46 | 2.05 | 0.96 |
| 2018 | 1.92 | 2.88 | 1.43 |
| 2017 | 2.34 | 2.74 | 1.85 |
| 2016 | 1.86 | 2.39 | 1.38 |
| 2015 | 2.36 | 3.71 | 1.58 |
| 2014 | 2.12 | 2.47 | 1.9 |
| 2013 | 2.53 | 3.04 | 1.95 |
| 2012 | 2.32 | 2.91 | 1.6 |
| 2011 | 6.91 | 14.53 | 2.58 |
| 2010 | 7.63 | 9.17 | 6.24 |
| 2009 | 7.19 | 9.38 | 5.72 |
| 2008 | 5.86 | 10.68 | 3.34 |
| 2007 | 5.06 | 6.66 | 3.17 |
| 2006 | 2.81 | 3.95 | 1.54 |
| 2005 | 1.77 | 2.45 | 1.29 |
| 2004 | 3.19 | 4.4 | 2.41 |
| 2003 | 3.43 | 4.29 | 2.3 |
| 2002 | 4.95 | 5.92 | 4.44 |
| 2001 | 6.4 | 7.87 | 4.54 |
| 2000 | 13.45 | 18.27 | 9.56 |
| 1999 | 8.95 | 13.21 | 6.46 |
| 1998 | 6.43 | 9.4 | 3.49 |
| 1997 | 3.98 | 6.08 | 3.08 |