20a. Self-employment as a percentage of the workforce, construction and all non-agricultural industries, 1980-2005
20b. Percentage of self-employed, by selected construction occupations, 2005 51% 40% 36% 36% 31% 22% 21% 21% 18% 17% 17% 15% 15% 14% 13% 12% 10% 9% 7% 7% 3% 3% 1% 24%
20c. Number of construction establishments, with and without payroll, 1967-2002
20d. Percentage of misclassified workers among employers engaged in misclassification, construction and other industries