Year annual % 1967 3.227722772277228 1968 19.998369460962977 1969 11.589533395731607 1970 19.568798796647805 1971 -1.156173246270892 1972 28.866666666666667 1973 35.11263697502704 1974 33.89258240801977 1975 21.145947070139865 1976 32.72961373390558 1977 19.386600271616118 1978 25.539319908454424 1979 46.99574982201031 1980 34.813015528223794 1981 85.96025192289896 1982 11.489892337144564 1983 40.03266172014892 1984 110.73820469937077 1985 127.42729330372396 1986 174.4277661068535 1987 153.38883384771097 1988 117.6640356453691 1989 68.57146549495994 1990 60.24090658889947 1991 51.663445272013284 1992 66.48933022407293 1993 57.21897371389291 1994 35.80456014752979 1995 13.944622055798225 1996 19.346594342949498 1997 19.417573296024056 1998 22.936850468913768 1999 13.558340257181317 2000 18.14214269912318 2001 9.788802688604306 2002 24.526993625340992 2003 17.932825839129492 2004 8.773715456047276 2005 17.182852689076 2006 16.9209410464131 2007 21.966047824206473 2008 30.816210357208785 2009 17.490866909378642 2010 38.08359780568083 2011 13.098047859547302 2012 15.505657391187203 2013 9.903239561349036 2014 14.608610336662538 2015 11.735618349836841 2016 11.13600174354447 2017 12.700074065213872 2018 8.232153102566752 2019 15.876139956879861 2020 17.13232421807163 2021 5.03542937653592 2022 7.502709028596254 2023 10.548782576817208