Year	% of revenue
1972	85.79104935902356
1973	85.79134324430996
1974	86.59040867837388
1975	86.1437727670955
1976	84.05922966694168
1977	83.60743928681217
1978	81.85155856309841
1979	83.14436885865457
1980	77.70458938927472
1981	74.32411674347158
1982	71.73223722842043
1983	68.66447034972124
1984	72.40459865641665
1985	77.7072711150521
1986	78.27117693543042
1987	78.48953819487433
1988	75.42847725774556
1989	75.44068542437812
1990	10.153710725893825
1991	8.090717567327461
1992	8.416010003953769
1993	6.984182677698171
1994	11.761811189041545
2022	9.212955373779431