Table 02. Average
Number of EMPLOYEES at Nonmetallic
Operations
in the United States,
by Primary Activity, 1978-2007
|
Year
|
Underground Mines
|
Surface Mines
|
|
|
Underground
|
Surf at UG
|
Total
|
Strip
|
Dredge
|
Other
|
Total
|
|
1978
|
6,082
|
1,232
|
7,314
|
11,346
|
28
|
290
|
11,664
|
|
1979
|
6,144
|
1,531
|
7,675
|
11,587
|
13
|
245
|
11,845
|
|
1980
|
6,612
|
2,322
|
8,934
|
12,068
|
13
|
386
|
12,467
|
|
1981
|
6,546
|
2,741
|
9,287
|
12,138
|
15
|
21
|
12,174
|
|
1982
|
5,736
|
2,231
|
7,967
|
9,497
|
11
|
18
|
9,526
|
|
1983 1/
|
4,220
|
814
|
5,034
|
7,521
|
78
|
17
|
7,616
|
|
1984
|
4,303
|
737
|
5,040
|
8,392
|
153
|
17
|
8,562
|
|
1985
|
3,858
|
721
|
4,579
|
8,942
|
192
|
16
|
9,150
|
|
1986
|
3,578
|
673
|
4,251
|
7,495
|
185
|
11
|
7,691
|
|
1987
|
3,323
|
631
|
3,954
|
6,869
|
185
|
-
|
7,054
|
|
1988
|
3,475
|
648
|
4,123
|
6,919
|
140
|
-
|
7,059
|
|
1989
|
3,703
|
714
|
4,417
|
7,016
|
176
|
-
|
7,192
|
|
1990
|
3,797
|
716
|
4.513
|
7,106
|
42
|
-
|
7,148
|
|
1991
|
3,644
|
637
|
4,281
|
6,590
|
80
|
-
|
6,670
|
|
1992
|
3,594
|
644
|
4,238
|
6,125
|
71
|
-
|
6,196
|
|
1993
|
3,317
|
614
|
3,931
|
5,967
|
20
|
-
|
5,987
|
|
1994
|
3,236
|
634
|
3,870
|
6,778
|
14
|
-
|
6,792
|
|
1995
|
3,345
|
559
|
3,904
|
5,821
|
11
|
-
|
5,832
|
|
1996
|
3,166
|
575
|
3,741
|
5,936
|
12
|
-
|
5,948
|
|
1997
|
3,082
|
422
|
3,504
|
5,808
|
13
|
-
|
5,821
|
|
1998
|
2,908
|
383
|
3,291
|
5,659
|
41
|
-
|
5,700
|
|
1999
|
2,745
|
416
|
3,161
|
5,602
|
57
|
12
|
5,671
|
|
2000
|
2,456
|
378
|
2,834
|
5,773
|
13
|
-
|
5,786
|
|
