Year US Dollars adjusted for inflation) 1962 1000000 1963 1000000 1964 0 1967 3000000 1971 1000000 1973 13000000 1974 8000000 1975 4000000 1976 1000000 1977 3000000 1978 4000000 1981 0 1985 5000000 1986 3000000 1989 4000000 1998 10000000 1999 10000000 2005 10000000 2006 10000000 2007 13000000 2008 2000000 2010 1000000 2013 1000000 2015 2000000 2016 22000000 2018 19000000 2019 3000000 2020 10000000 2021 28000000