| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | -0.98 | |
| 2022 | 0.54 | 0.71 | 0.39 |
| 2021 | 0.78 | 1.09 | 0.35 |
| 2020 | 0.98 | 1.24 | 0.66 |
| 2019 | 0.84 | 1.12 | 0.67 |
| 2018 | 1.18 | 1.75 | 0.66 |
| 2017 | 1.72 | 2.25 | 1.19 |
| 2016 | 2.21 | 3.68 | 1.34 |
| 2015 | 4.4 | 9.54 | 2.45 |
| 2014 | 2.19 | 3.28 | 1.56 |
| 2013 | 1.81 | 2.23 | 1.37 |
| 2012 | 2.8 | 4.28 | 1.59 |
| 2011 | 2.45 | 2.99 | 1.77 |
| 2010 | 3.19 | 5.11 | 2.17 |
| 2009 | 3.08 | 4.8 | 1.16 |
| 2008 | 2.02 | 4.48 | 0.86 |
| 2007 | 3.58 | 4.95 | 2.39 |
| 2006 | 2.34 | 3.47 | 1.47 |
| 2005 | 1.84 | 2.38 | 1.39 |
| 2004 | 2.77 | 4.4 | 1.5 |