| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.1 | 1.3 | 0.99 |
| 2024 | 1.08 | 1.24 | 0.88 |
| 2023 | 1.46 | 1.74 | 1.2 |
| 2022 | 1.93 | 2.6 | 1.53 |
| 2021 | 1.62 | 2.95 | 1.2 |
| 2020 | 1.86 | 2.42 | 1.65 |
| 2019 | 2.79 | 3.82 | 2.22 |
| 2018 | 3.61 | 5.5 | 2.73 |
| 2017 | 5.09 | 10.35 | 4.38 |
| 2016 | 10.78 | 20.73 | 5.21 |
| 2015 | 3.1 | 5.21 | 1.81 |
| 2014 | 1.6 | 2.13 | 1.28 |
| 2013 | 1.89 | 2.51 | 1.34 |
| 2012 | 2.48 | 3.43 | 1.63 |
| 2011 | 3.9 | 5.31 | 2.29 |
| 2010 | 3.29 | 4.48 | 2.17 |
| 2009 | 3.67 | 5.6 | 2.09 |
| 2008 | 4.95 | 8.81 | 1.46 |
| 2007 | 3.86 | 7.71 | 1.27 |
| 2006 | 1.23 | 1.49 | 1.07 |
| 2005 | 1.75 | 2.67 | 1 |
| 2004 | 2.73 | 3.34 | 2.2 |
| 2003 | 2.05 | 2.6 | 1.73 |
| 2002 | 2.76 | 3.14 | 2.26 |
| 2001 | 3.58 | 4.34 | 2.61 |