| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.18 | 0.21 | 0.17 |
| 2024 | 0.17 | 0.24 | 0.12 |
| 2023 | 0.1 | 0.26 | 0.03 |
| 2022 | 0.28 | 0.39 | 0.21 |
| 2021 | 0.26 | 0.34 | 0.18 |
| 2020 | 0.23 | 0.3 | 0.2 |
| 2019 | 0.33 | 0.45 | 0.2 |
| 2018 | 0.51 | 0.7 | 0.41 |
| 2017 | 0.98 | 1.3 | 0.66 |
| 2016 | 1.31 | 1.57 | 1.19 |
| 2015 | 1.57 | 2.44 | 0.96 |
| 2014 | 1.02 | 1.49 | 0.77 |
| 2013 | 40.51 | 41.5 | 35.99 |
| 2012 | 24.69 | 37.85 | 18.27 |
| 2011 | 44.84 | 109.47 | 23.36 |
| 2010 | 23.3 | 36.65 | 15.1 |
| 2009 | 17.12 | 32.43 | 3.15 |
| 2008 | 4.57 | 8.35 | 2.32 |
| 2007 | 4.14 | 8.28 | 1.76 |
| 2006 | 1.59 | 3.08 | 0.95 |
| 2005 | 0.28 | 0.98 | 0.03 |
| 2004 | 0.07 | 0.11 | 0.04 |