Year annual % growth 1971 14.865828619428683 1972 -8.368938964171619 1973 27.268897436380882 1974 8.380203473149479 1975 33.07325513363264 1976 64.41876672809715 1977 -21.306930508283642 1978 -33.23591789745079 1979 -51.65546524182476 1980 212.18984379684207 1981 44.638209423998745 1982 4.141605355962071 1983 -5.8413544710513605 1984 -2.6432381527925912 1985 -16.21059360803244 1986 -18.378829710018252 1987 -26.368415923869676 1988 37.11977757985076 1989 -12.5966417751697 1990 -13.159547264471882 1991 27.076218895500844 1992 -17.79595249888925 1993 -16.521357454412737 1994 25.562996534365 1995 -5.0348000344334025 1996 13.521196461008827 1997 7.48750809625507 1998 10.019494649938167 1999 -2.331294694640775 2000 -18.000894239549652 2001 27.215405670791128 2002 11.202868055565858 2003 1.64502477653528 2004 -1.126138908124858 2005 12.240753661359506 2006 -2.4328687582518427 2007 0.42675821663226543 2008 6.999752052271319 2009 3.9461445569811957 2010 3.914249417018027 2011 15.423402396778869 2012 11.935635361996418 2013 12.728321181443846 2014 15.827286237188474 2015 5.058513556114292 2016 1.2142609646183473 2017 1.1465004589132946 2018 27.998629997773406 2019 6.631992884708865 2020 -7.643899140387404 2021 3.310400709426034