Year	% of revenue
1983	13.236624342524037
1984	12.91007860155989
1985	10.634844614729671
1986	8.135189049136725
1987	9.617275476318571
1988	10.531042327725558
1989	12.731713020095867
1990	13.68262009509843
1991	19.807131019427096
1992	15.107244739463734
1993	13.820589829625645
1994	15.830877627521641
1995	19.57971556960049
1996	19.098469401151142
1997	18.48909207863889
1998	19.779340821856305
1999	26.180998873450996
2000	22.145880820579617
2001	21.409544950055494
2002	21.764749646603676
2003	22.86634988782813
2004	20.576471890626927
2005	20.587529110615947
2006	19.76519553298469
2007	20.859243808176036
2008	20.777124533747735
2009	22.160021905328993
2010	24.776785714285715
2011	22.701281616085282
2012	18.42856216663322
2013	19.958382352941175
2014	22.078215303946738
2015	22.103223064455754
2016	19.78697994074298
2017	22.32432672662042
2018	22.44870199199712
2019	23.314395866397632
2020	22.294175581393823
2021	25.026630167111456
2022	24.671742921318497