Occupation	years	Total
Total	2001	23,468
Total	2000	22,400
Total	1999	22,283
Total	1998	20,170
Total	1997	19,189
Total	1996	17,866
Total	1995	17,153
Total	1994	17,546
Total	1993	17,266
Total	1992	16,678
Total	1991	17,519
Total	1990	17,170
Total	1989	14,606
Total	1988	13,747
Total	1987	12,643
Total	1986	11,636
Total	1985	10,031
Total	1984	10,695
Total	1983	10,213
Total	1982	10,595
Total	1981	11,805
Total	1980	11,400
Total	1979	11,115
Total	1978	11,041
Total	1977	..
Total	1976	11,553
Total	1975	11,438
Total	1974	9,423
Total	1973	8,886
Total	1972	12,063
Total	1971	11,661
Total	1970	9,058
Total	1969	8,579
Researchers	2001	13,345
Researchers	2000	12,708
Researchers	1999	11,935
Researchers	1998	11,021
Researchers	1997	10,490
Researchers	1996	9,126
Researchers	1995	8,359
Researchers	1994	7,820
Researchers	1993	7,737
Researchers	1992	7,660
Researchers	1991	8,079
Researchers	1990	7,623
Researchers	1989	5,864
Researchers	1988	5,706
Researchers	1987	4,528
Researchers	1986	4,060
Researchers	1985	2,839
Researchers	1984	2,917
Researchers	1983	2,872
Researchers	1982	3,351
Researchers	1981	3,632
Researchers	1980	3,536
Researchers	1979	3,369
Researchers	1978	3,197
Researchers	1977	..
Researchers	1976	3,239
Researchers	1975	3,278
Researchers	1974	2,991
Researchers	1973	2,703
Researchers	1972	4,499
Researchers	1971	4,364
Researchers	1970	3,261
Researchers	1969	3,037
Technicians	2001	5,659
Technicians	2000	4,760
Technicians	1999	4,879
Technicians	1998	4,087
Technicians	1997	3,826
Technicians	1996	3,343
Technicians	1995	3,364
Technicians	1994	4,005
Technicians	1993	3,835
Technicians	1992	2,588
Technicians	1991	2,586
Technicians	1990	2,598
Technicians	1989	2,549
Technicians	1988	2,306
Technicians	1987	1,638
Technicians	1986	1,375
Technicians	1985	1,470
Technicians	1984	1,554
Technicians	1983	1,256
Technicians	1982	1,094
Technicians	1981	1,242
Technicians	1980	1,161
Technicians	1979	1,081
Technicians	1978	749
Technicians	1977	..
Technicians	1976	846
Technicians	1975	..
Technicians	1974	825
Technicians	1973	992
Technicians	1972	747
Technicians	1971	732
Technicians	1970	543
Technicians	1969	498
Assistants	2001	4,464
Assistants	2000	4,932
Assistants	1999	5,470
Assistants	1998	5,062
Assistants	1997	4,873
Assistants	1996	5,397
Assistants	1995	5,430
Assistants	1994	5,722
Assistants	1993	5,695
Assistants	1992	6,430
Assistants	1991	6,855
Assistants	1990	6,949
Assistants	1989	6,193
Assistants	1988	5,735
Assistants	1987	6,478
Assistants	1986	6,201
Assistants	1985	5,723
Assistants	1984	6,224
Assistants	1983	6,085
Assistants	1982	6,150
Assistants	1981	6,931
Assistants	1980	6,703
Assistants	1979	6,665
Assistants	1978	7,095
Assistants	1977	..
Assistants	1976	7,468
Assistants	1975	..
Assistants	1974	5,607
Assistants	1973	5,191
Assistants	1972	6,817
Assistants	1971	6,565
Assistants	1970	5,254
Assistants	1969	5,044