
| 2024 | 0.37 | 0.94 | 97.55 | 39% |
| 2023 | 0.34 | 0.93 | 95.91 | 36.7% |
| 2022 | 0.34 | 0.99 | 102.6 | 34.1% |
| 2021 | 0.34 | 1.07 | 109.7 | 32% |
| 2020 | 0.34 | 1.02 | 104.9 | 33.7% |
| 2019 | 0.36 | 1.04 | 106.7 | 34.1% |
| 2018 | 0.36 | 1.05 | 107.5 | 34.2% |
| 2017 | 0.36 | 1.03 | 105.6 | 34.4% |
| 2016 | 0.36 | 0.99 | 100.7 | 36.5% |
| 2015 | 0.35 | 0.97 | 99.03 | 36.2% |
| 2014 | 0.35 | 0.93 | 94.49 | 37.9% |
| 2013 | 0.35 | 0.91 | 92.5 | 38.7% |
| 2012 | 0.36 | 0.94 | 95.14 | 38.6% |
| 2011 | 0.38 | 1.01 | 101.2 | 37.6% |
| 2010 | 0.39 | 1.04 | 104 | 37.7% |
| 2009 | 0.39 | 1.02 | 101.7 | 38.5% |
| 2008 | 0.38 | 1.1 | 109.5 | 34.3% |
| 2007 | 0.37 | 1.1 | 109.9 | 33.3% |
| 2006 | 0.37 | 1.14 | 113.1 | 33% |
| 2005 | 0.38 | 1.15 | 114.2 | 33.1% |
| 2004 | 0.37 | 1.07 | 106.3 | 34.9% |
| 2003 | 0.37 | 1.06 | 105.3 | 34.9% |
| 2002 | 0.39 | 1.04 | 102.6 | 37.7% |
| 2001 | 0.42 | 1.04 | 102.7 | 39.8% |
| 2000 | 0.41 | 1.01 | 99.12 | 40.9% |
| 1999 | 0.42 | 1.04 | 101.5 | 40.7% |
| 1998 | 0.44 | 1.04 | 101.7 | 42.3% |
| 1997 | 0.47 | 1.05 | 101.9 | 45% |
| 1996 | 0.49 | 1.07 | 103.9 | 45.9% |
| 1995 | 0.51 | 1.04 | 100.6 | 49% |
| 1994 | 0.48 | 1.03 | 99.52 | 46.7% |
| 1993 | 0.52 | 1.03 | 99.81 | 50.2% |
| 1992 | 0.53 | 1.01 | 97.6 | 52.3% |
| 1991 | 0.54 | 1.11 | 107.2 | 48.7% |
| 1990 | 0.57 | 1.14 | 109.8 | 49.6% |
| 1989 | 0.62 | 1.21 | 116.1 | 51.4% |
| 1988 | 0.63 | 1.2 | 115.2 | 52.4% |
| 1987 | 0.64 | 1.22 | 116.9 | 52.6% |
| 1986 | 0.61 | 1.2 | 114.4 | 51% |
| 1985 | 0.62 | 1.2 | 114 | 51.7% |
| 1984 | 0.58 | 1.13 | 107.1 | 51.2% |
| 1983 | 0.43 | 1.17 | 109.9 | 36.8% |
| 1982 | 0.42 | 1.15 | 107.8 | 36.4% |
| 1981 | 0.4 | 1.15 | 108 | 34.4% |
| 1980 | 0.4 | 1.17 | 109.2 | 34.4% |