| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0.85 | 0.95 | 0.73 |
| 2023 | 0.84 | 1.01 | 0.6 |
| 2022 | 0.71 | 1.01 | 0.56 |
| 2021 | 1.38 | 1.89 | 0.94 |
| 2020 | 1.42 | 1.79 | 1.09 |
| 2019 | 1.26 | 1.64 | 0.95 |
| 2018 | 1.52 | 2.5 | 0.96 |
| 2017 | 1.94 | 2.51 | 1.53 |
| 2016 | 1.73 | 2.16 | 1.5 |
| 2015 | 3.26 | 5.04 | 2.12 |
| 2014 | 2.13 | 3.5 | 0.83 |
| 2013 | 1.13 | 1.58 | 0.82 |
| 2012 | 1.81 | 2.62 | 1.27 |
| 2011 | 3.87 | 4.84 | 2.21 |
| 2010 | 4.88 | 8.58 | 3.04 |
| 2009 | 4.96 | 8.75 | 0.86 |
| 2008 | 1.9 | 4.43 | 0.58 |
| 2007 | 2.23 | 3.81 | 0.63 |
| 2006 | 0.55 | 0.71 | 0.4 |
| 2005 | 0.3 | 0.62 | 0.14 |
| 2004 | 0.44 | 0.82 | 0.21 |