| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.08 | 1.4 | 0.78 |
| 2023 | 1.17 | 1.53 | 0.68 |
| 2022 | 1.54 | 2.41 | 1.05 |
| 2021 | 0.83 | 1.63 | 0.45 |
| 2020 | 0.5 | 0.6 | 0.43 |
| 2019 | 0.63 | 0.82 | 0.53 |
| 2018 | 1 | 1.49 | 0.62 |
| 2017 | 1.23 | 1.49 | 1.03 |
| 2016 | 1.24 | 1.5 | 0.99 |
| 2015 | 1.51 | 2.39 | 1.04 |
| 2014 | 1.16 | 1.67 | 0.92 |
| 2013 | 1.9 | 3 | 1.19 |
| 2012 | 3.21 | 4.36 | 1.99 |
| 2011 | 5.99 | 8.5 | 3.15 |
| 2010 | 6.54 | 9.93 | 4.4 |
| 2009 | 6.52 | 9.36 | 3.62 |
| 2008 | 5.32 | 10.13 | 2.19 |
| 2007 | 5.73 | 11.62 | 2.56 |
| 2006 | 2.15 | 2.74 | 1.76 |
| 2005 | 2.18 | 3.01 | 1.58 |
| 2004 | 2.89 | 3.52 | 2.44 |