Table 1.

Number and Percentage of Census Occupations

by Six Kinds of Work, 1960-1990

	Census Year
	1960		1970		1980		1990
Kind of Work	N	%	N	%	N	%	N	%
R	141	50	216	46	238	47	241	48
I	40	14	51	11	59	12	60	12
A	14	5	18	4	14	3	10	2
S	39	14	70	15	47	9	51	10
E	27	10	75	16	100	20	95	19
C	21	7	35	8	44	9	43	9
Total	282	100	465	100	502	100	500	100