Year % of revenue 1995 0.2923026956804157 1996 2.424433249370277 1997 0.8863819500402902 1998 0.7490636704119851 1999 1.7705698556762386 2009 0.15325443786982249 2010 0.07358615862304145 2012 3.482711285275549 2013 2.2249636658340153 2014 2.369917609698451 2015 1.4941205043031918 2016 1.3490709164862602 2017 1.5042019655398764 2018 1.4603019926728587 2019 1.3493928357676948 2020 1.2530852957837664 2021 1.0294035670482249