Percent of total employer compensation cost for legally-required benefits, all workers, all private establishments, 1966-1998 Benefit 1966 1977 1988 1998 Total legally required 5.1 6.8 8.8 8.2 Social Security 2.8 3.7 4.8 4.7 Medicare 0.3 0.7 1.1 1.2 Unemployment insurance 1.1 1.2 1.0 0.7 Workers' compensation 0.9 1.2 1.7 1.8