| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.24 | 1.34 | 1.12 |
| 2024 | 0.93 | 2.25 | 0.64 |
| 2023 | 1.06 | 1.13 | 0.93 |
| 2022 | 1.07 | 1.46 | 0.89 |
| 2021 | 0.93 | 1.23 | 0.82 |
| 2020 | 1.09 | 1.36 | 0.94 |
| 2019 | 1.43 | 1.99 | 1.1 |
| 2018 | 1.83 | 2.72 | 1.17 |
| 2017 | 3.96 | 8.8 | 2.22 |
| 2016 | 3.96 | 6 | 3.01 |
| 2015 | 4.29 | 8.69 | 2.66 |
| 2014 | 12.85 | 40.39 | 1.96 |
| 2013 | 26.81 | 31.75 | 20.66 |
| 2012 | 19.07 | 23.87 | 13.28 |
| 2011 | 21.17 | 23.9 | 13.67 |
| 2010 | 19.17 | 23.1 | 14.68 |
| 2009 | 17.63 | 21.84 | 11.16 |
| 2008 | 27.61 | 88.18 | 7.5 |
| 2007 | 22.12 | 59.68 | 5.03 |
| 2006 | 3.76 | 5.42 | 2.59 |
| 2005 | 3.16 | 4.13 | 2.03 |
| 2004 | 5.39 | 7.43 | 3.91 |
| 2003 | 9.16 | 12.08 | 5.25 |
| 2002 | 12.91 | 15.14 | 9.62 |
| 2001 | 15.82 | 21.63 | 10.92 |
| 2000 | 11.83 | 17.98 | 7.86 |
| 1999 | 8.04 | 10.19 | 6.8 |
| 1998 | 7.11 | 8.87 | 5.12 |
| 1997 | 6.65 | 8.98 | 4.77 |