| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | -0.36 | |
| 2022 | 0 | -2.12 | |
| 2021 | 28.14 | 61.56 | 6.69 |
| 2020 | 5.98 | 9.13 | 1.25 |
| 2019 | 2.13 | 3.72 | 1.55 |
| 2018 | 2.97 | 5.74 | 1.75 |
| 2017 | 6.32 | 9.26 | 5.7 |
| 2016 | 10.17 | 14.18 | 8.57 |
| 2015 | 13.58 | 26.78 | 6.55 |
| 2014 | 4.64 | 9.64 | 2.3 |
| 2013 | 2.69 | 3.29 | 2.11 |
| 2012 | 2.13 | 2.54 | 1.56 |
| 2011 | 2.97 | 4.09 | 2.04 |
| 2010 | 3.76 | 4.96 | 2.75 |
| 2009 | 3 | 4.39 | 1.32 |
| 2008 | 2.16 | 4.52 | 0.94 |
| 2007 | 3.3 | 5.66 | 1.25 |
| 2006 | 1.18 | 1.46 | 0.85 |
| 2005 | 1.22 | 1.72 | 0.92 |
| 2004 | 2.1 | 2.79 | 1.68 |
| 2003 | 2.35 | 2.76 | 1.96 |
| 2002 | 4.9 | 9.9 | 2.68 |
| 2001 | 11.01 | 13.9 | 9.1 |
| 2000 | 15.93 | 19.69 | 10.97 |
| 1999 | 8.1 | 13.18 | 4.47 |