| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.8 | 0.9 | 0.7 |
| 2024 | 0.64 | 1.14 | 0.45 |
| 2023 | 0.75 | 0.84 | 0.66 |
| 2022 | 0.83 | 1.12 | 0.6 |
| 2021 | 1.19 | 1.58 | 0.89 |
| 2020 | 1.26 | 1.64 | 1.09 |
| 2019 | 1.74 | 2.63 | 1.12 |
| 2018 | 4.76 | 10.2 | 1.94 |
| 2017 | 25.17 | 62.24 | 8.26 |
| 2016 | 48.44 | 87.9 | 8.33 |
| 2015 | 6.41 | 11.29 | 1.96 |
| 2014 | 1.29 | 2.38 | 0.93 |
| 2013 | 1.19 | 1.56 | 0.99 |
| 2012 | 0.96 | 1.22 | 0.75 |
| 2011 | 1.05 | 1.38 | 0.77 |
| 2010 | 1.34 | 1.95 | 1.02 |
| 2009 | 1.47 | 2.65 | 0.7 |
| 2008 | 1.39 | 2.97 | 0.55 |
| 2007 | 2.14 | 4.32 | 0.98 |
| 2006 | 0.76 | 0.92 | 0.61 |
| 2005 | 0.88 | 1.26 | 0.58 |
| 2004 | 1.73 | 2.7 | 1.23 |
| 2003 | 1.84 | 2.64 | 1.4 |
| 2002 | 1.49 | 1.71 | 1.31 |
| 2001 | 1.75 | 2.2 | 1.33 |
| 2000 | 1.79 | 2.36 | 1.29 |
| 1999 | 1.57 | 2.08 | 1.28 |
| 1998 | 2.85 | 3.59 | 2.19 |