| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.55 | 0.63 | 0.45 |
| 2024 | 0.53 | 0.64 | 0.4 |
| 2023 | 0.7 | 0.8 | 0.61 |
| 2022 | 0.72 | 0.87 | 0.6 |
| 2021 | 0.86 | 1.04 | 0.74 |
| 2020 | 0.72 | 1.1 | 0.45 |
| 2019 | 1.13 | 2.7 | 0.43 |
| 2018 | 1.64 | 2.23 | 1.13 |
| 2017 | 2.11 | 2.6 | 1.63 |
| 2016 | 1.91 | 2.58 | 1.45 |
| 2015 | 2.01 | 3.9 | 0.93 |
| 2014 | 0.63 | 1.11 | 0.47 |
| 2013 | 0.54 | 0.63 | 0.48 |
| 2012 | 0.66 | 0.91 | 0.47 |
| 2011 | 1.2 | 1.6 | 0.78 |
| 2010 | 1.58 | 2.08 | 1.16 |
| 2009 | 1.2 | 1.82 | 0.67 |
| 2008 | 1.34 | 2.35 | 0.5 |
| 2007 | 1.75 | 2.46 | 1.28 |
| 2006 | 1.3 | 1.76 | 1.03 |
| 2005 | 0.92 | 1.52 | 0.58 |
| 2004 | 1.13 | 2.34 | 0.64 |