| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.72 | 2.15 | 1.45 |
| 2024 | 1.24 | 2.38 | 0.67 |
| 2023 | 1.42 | 1.84 | 1.25 |
| 2022 | 1.25 | 1.82 | 0.99 |
| 2021 | 1.15 | 1.32 | 1 |
| 2020 | 1.18 | 1.54 | 1.03 |
| 2019 | 1.39 | 1.88 | 1.19 |
| 2018 | 1.66 | 2.56 | 1.06 |
| 2017 | 2.63 | 4.2 | 2.01 |
| 2016 | 3.01 | 4.14 | 2.22 |
| 2015 | 3.94 | 6.08 | 2.54 |
| 2014 | 3.31 | 4.5 | 2.5 |
| 2013 | 4.08 | 7.16 | 2.71 |
| 2012 | 3.35 | 4.22 | 2.43 |
| 2011 | 10.2 | 28.02 | 3.87 |
| 2010 | 12.13 | 16.39 | 9.32 |
| 2009 | 10.61 | 15.4 | 8.6 |
| 2008 | 0 | ||
| 2007 | 0 | ||
| 2006 | 0 | -0.5 | |
| 2005 | 2.28 | 2.69 | 1.64 |
| 2004 | 2.65 | 3.22 | 1.97 |
| 2003 | 3.75 | 5.11 | 1.94 |
| 2002 | 4.95 | 5.93 | 3.99 |
| 2001 | 5.58 | 8.23 | 3.71 |
| 2000 | 8.25 | 11.65 | 4.81 |
| 1999 | 3.75 | 4.78 | 3.03 |