| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.55 | 2.32 | 1.16 |
| 2024 | 1.23 | 2.04 | 0.88 |
| 2023 | 1.51 | 1.77 | 1.23 |
| 2022 | 1.29 | 1.73 | 0.9 |
| 2021 | 1.47 | 2.2 | 1.11 |
| 2020 | 1.21 | 1.52 | 0.99 |
| 2019 | 1.29 | 1.73 | 1.04 |
| 2018 | 1.78 | 2.53 | 1.34 |
| 2017 | 3.7 | 5.93 | 2.12 |
| 2016 | 2.77 | 6.71 | 1.6 |
| 2015 | 2.08 | 3.32 | 1.35 |
| 2014 | 1.21 | 1.85 | 0.9 |
| 2013 | 0.95 | 1.12 | 0.76 |
| 2012 | 0.99 | 1.41 | 0.68 |
| 2011 | 1.17 | 1.63 | 0.66 |
| 2010 | 1.36 | 2.3 | 0.95 |
| 2009 | 1.31 | 2.24 | 0.62 |
| 2008 | 1.63 | 2.99 | 0.42 |
| 2007 | 1.8 | 3.04 | 0.77 |
| 2006 | 1.15 | 1.83 | 0.77 |
| 2005 | 2.15 | 3.01 | 1.23 |
| 2004 | 2.92 | 4.62 | 2.02 |