Year annual % 1974 26.39533292699613 1975 11.497544605513074 1976 16.45512639457704 1977 13.66995353913551 1978 17.182863810635105 1979 10.160744260149649 1980 12.761748329046188 1981 15.9975081192255 1982 14.049116821267372 1983 -0.6834943388386828 1984 6.278849237892035 1985 2.8168321053909184 1986 8.433700344252202 1987 3.9362456490332987 1988 10.255771490042322 1989 5.314360687390397 1990 30.09157156405499 1991 104.02422873103512 1992 94.69554106895669 1993 172.16673979401676 1994 125.44687222809384 1995 69.6181851202503 1996 69.54519286125503 1997 113.4296752804032 1998 53.74884592594634 1999 50.39908287528701 2000 40.80977577498729 2001 18.02225253966275 2002 46.597095917484985 2003 21.072333225196072 2004 48.42117864676633 2005 20.04289056958937 2006 14.12674163591387 2007 33.8338795224371 2008 17.493717786934457 2009 9.033322075529476 2010 6.817370532677009 2011 6.467014117257486 2012 2.842452226080585 2013 8.80537482390374 2014 8.330173682156945 2015 9.393466614163493 2016 9.740684525259153 2017 11.407673893370198 2018 8.887979859537415 2019 10.90510873962897 2020 15.313069259071721 2021 15.814728647083978 2022 6.8422111441241755 2023 10.731500627043394