| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.59 | 1.76 | 1.41 |
| 2024 | 0.8 | 1.78 | 0.36 |
| 2023 | 0.61 | 0.9 | 0.42 |
| 2022 | 0.98 | 1.72 | 0.68 |
| 2021 | 0.77 | 1 | 0.63 |
| 2020 | 0.94 | 1.15 | 0.62 |
| 2019 | 1.09 | 1.75 | 0.64 |
| 2018 | 1.2 | 1.56 | 1.03 |
| 2017 | 1.38 | 1.7 | 1.16 |
| 2016 | 1.97 | 2.95 | 1.47 |
| 2015 | 2.07 | 3.95 | 0.99 |
| 2014 | 0.9 | 1.13 | 0.7 |
| 2013 | 1.28 | 1.78 | 1 |
| 2012 | 1.51 | 1.91 | 1.17 |
| 2011 | 2.81 | 3.69 | 1.41 |
| 2010 | 3.62 | 5.93 | 2.51 |
| 2009 | 5.05 | 8.45 | 2.04 |
| 2008 | 2.61 | 4.07 | 1.22 |
| 2007 | 3.22 | 5.09 | 1.78 |
| 2006 | 1.62 | 1.98 | 1.29 |
| 2005 | 1.72 | 2.41 | 1.14 |
| 2004 | 2.92 | 4.97 | 1.73 |