| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.64 | 2.04 | 1.32 |
| 2024 | 1.55 | 2.16 | 1.09 |
| 2023 | 2.35 | 3.86 | 1.53 |
| 2022 | 2.94 | 4.2 | 2.27 |
| 2021 | 3.24 | 4.21 | 2.76 |
| 2020 | 2.62 | 3.77 | 2.1 |
| 2019 | 2.6 | 3.89 | 1.76 |
| 2018 | 3.01 | 4.72 | 1.91 |
| 2017 | 3.69 | 5.11 | 2.81 |
| 2016 | 8.54 | 11.77 | 4.13 |
| 2015 | 7.63 | 13.79 | 3.84 |
| 2014 | 3.35 | 3.89 | 2.74 |
| 2013 | 13.81 | 52.41 | 3.44 |
| 2012 | 6.09 | 10.32 | 3.34 |
| 2011 | 8.07 | 9.84 | 4.28 |
| 2010 | 6.61 | 8.84 | 2.23 |
| 2009 | 1.76 | 2.95 | 0.91 |
| 2008 | 1.68 | 3.57 | 0.69 |
| 2007 | 2.15 | 4.15 | 0.62 |
| 2006 | 0.65 | 0.91 | 0.56 |
| 2005 | 0.9 | 1.45 | 0.57 |
| 2004 | 1.9 | 2.43 | 1.38 |
| 2003 | 1.85 | 2.14 | 1.48 |
| 2002 | 2.8 | 4.21 | 2.23 |
| 2001 | 4.46 | 5.94 | 3.35 |
| 2000 | 4.47 | 6.05 | 2.91 |