Year | Value | 2022 | 1.8571720836759 | 2021 | 1.8347881615013 | 2020 | 1.9561353908415 | 2019 | 1.8757233086332 | 2018 | 1.8732739179236 | 2017 | 1.9415089011249 | 2016 | 2.0575124534874 | 2015 | 2.0571189301627 | 2014 | 2.0997276673851 | 2013 | 2.1030985700624 | 2012 | 2.073827173866 | 2011 | 2.0082342729307 | 2010 | 2.0799274779115 | 2009 | 2.2050052500869 | 2008 | 2.0256026663906 | 2007 | 2.0285006537883 | 2006 | 2.0835795130405 | 2005 | 2.1236517897143 | 2004 | 2.183221367476 | 2003 | 2.2781085921136 | 2002 | 2.3804944268388 | 2001 | 2.3710527428294 | 2000 | 2.2843083210033 | 1999 | 2.2556302440102 | 1998 | 2.1736515864164 | 1997 | 2.3332773049291 | 1996 | 2.3190078515972 | 1995 | 2.4283553297955 | 1994 | 2.7098241806896 | 1993 | 2.729373971305 | 1992 | 3.1739341727763 | 1989 | 2.9392626200146 |
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