| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.11 | 1.21 | 1.01 |
| 2024 | 1.12 | 1.48 | 0.9 |
| 2023 | 1.39 | 1.8 | 1.14 |
| 2022 | 1.61 | 1.97 | 1.33 |
| 2021 | 1.73 | 2.35 | 1.43 |
| 2020 | 2.51 | 3.08 | 2.16 |
| 2019 | 2.44 | 3.36 | 1.84 |
| 2018 | 2.41 | 3.29 | 1.75 |
| 2017 | 4.31 | 5.72 | 2.99 |
| 2016 | 4.72 | 5.89 | 3.74 |
| 2015 | 7.22 | 10.5 | 4.58 |
| 2014 | 5.07 | 6.54 | 4.03 |
| 2013 | 4.29 | 5.45 | 3.16 |
| 2012 | 5.46 | 6.67 | 4.16 |
| 2011 | 5.69 | 7.16 | 4.84 |
| 2010 | 6.43 | 8.68 | 4.9 |
| 2009 | 7.22 | 8.76 | 6.34 |
| 2008 | 0 | ||
| 2007 | 0 | ||
| 2006 | 0 | -0.69 | |
| 2005 | 2.26 | 2.67 | 1.33 |
| 2004 | 3.21 | 4.27 | 2.54 |
| 2003 | 3.74 | 4.53 | 1.29 |
| 2002 | 1.74 | 2.25 | 1.09 |
| 2001 | 1.8 | 2.06 | 1.44 |
| 2000 | 1.84 | 2.17 | 1.51 |
| 1999 | 1.34 | 1.7 | 1.09 |
| 1998 | 1.79 | 2.22 | 1.37 |
| 1997 | 2.89 | 5.24 | 1.8 |