Year | Value | 2019 | 0.116 | 2018 | 0.132 | 2017 | 0.135 | 2016 | 0.12 | 2015 | 0.11 | 2014 | 0.089 | 2013 | 0.099 | 2011 | 0.0129 | 2010 | 0.055 | 2009 | 0.055 | 2008 | 0.052 | 2005 | 0.024 | 2004 | 0.049 | 2002 | 0.019 | 1993 | 0.04 | 1989 | 0.04 | 1985 | 0.027 | 1983 | 0.029 | 1981 | 0.031 | 1980 | 0.032 | 1975 | 0.017 | 1970 | 0.017 | 1965 | 0.014 | 1960 | 0.008 |
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