Year annual % 1961 9.69030969030969 1962 9.289617486338798 1963 13.333333333333334 1964 17.86764705882353 1965 18.83967560823456 1966 23.04461942257218 1967 15.656996587030717 1968 15.19734415344891 1969 17.034902337495996 1970 21.896032831395345 1971 28.130541153312155 1972 26.027397260111997 1973 28.422106082781127 1974 25.664559702173435 1975 28.010232205638918 1976 23.43010933559582 1977 33.8003139854576 1978 36.53148858856269 1979 61.724983736669024 1980 74.04442263192576 1981 88.3647362020955 1982 51.14404788370136 1983 29.713446296547986 1984 58.70532510406201 1985 55.18314190105815 1986 66.08930798549999 1987 53.321215779020726 1988 65.06417298326559 1989 69.0368505264559 1990 53.07843610098117 1991 82.92999719225749 1992 78.14060136545083 1993 64.22198164447315 1994 144.79679228340945 1995 104.18957535631293 1996 116.53975281304542 1997 97.79596297865199 1998 89.31653726692242 1999 101.99090359658342 2000 40.65796037043809 2001 90.36813458197344 2002 27.885454838646645 2003 14.43683138943718 2004 20.79169230294494 2005 35.967453596549326 2006 22.17427552054378 2007 15.225666782543708 2008 24.823689261755536 2009 12.659447539704969 2010 18.546859090393255 2011 15.204026614265246 2012 10.422274683865506 2013 21.152821760572845 2014 11.18342526188194 2015 16.514655808082367 2016 17.64878823266816 2017 16.351922419018404 2018 18.38002716014252 2019 27.023086495456717 2020 34.24288531672965 2021 52.51794426044306 2022 60.339327263069286 2023 69.93635188782665