Year US Dollars adjusted for inflation) 1977 3000000 1978 6000000 1979 36000000 1980 5000000 1981 2000000 1982 3000000 1983 3000000 1985 1000000 1986 8000000 1987 1000000 1991 1000000 1992 19000000 1993 5000000 1995 2000000 2000 1000000 2002 3000000 2004 4000000 2005 7000000 2012 6000000 2013 5000000 2014 15000000 2015 1000000 2016 10000000 2019 8000000 2020 1000000 2021 45000000 2022 17000000