Table 02. Average Number of EMPLOYEES at Metallic 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
|
19,697
|
4,441
|
24,138
|
24,705
|
407
|
77
|
25,189
|
|
1979
|
20,935
|
5,082
|
26,017
|
27,079
|
348
|
65
|
27,492
|
|
1980
|
21,333
|
6,216
|
27,549
|
26,705
|
354
|
90
|
27,149
|
|
1981
|
21,665
|
6,882
|
28,547
|
28,572
|
343
|
16
|
28,931
|
|
1982
|
14,701
|
4,827
|
19,528
|
17,016
|
417
|
7
|
17,440
|
|
19831
|
9,322
|
3,348
|
12,670
|
12,396
|
341
|
-
|
12,737
|
|
1984
|
9,292
|
2,476
|
11,768
|
11,814
|
348
|
-
|
12,162
|
|
1985
|
8,177
|
2,084
|
10,261
|
10,552
|
345
|
-
|
10,897
|
|
1986
|
7,071
|
1,844
|
8,915
|
9,971
|
401
|
-
|
10,372
|
|
1987
|
6,883
|
1,902
|
8,785
|
11,692
|
476
|
-
|
12,168
|
|
1988
|
7,452
|
2,022
|
9,474
|
13,876
|
474
|
-
|
14,350
|
|
1989
|
7,751
|
2,172
|
9,923
|
15,940
|
464
|
-
|
16,404
|
|
1990
|
7,552
|
2,313
|
9,835
|
17,301
|
425
|
-
|
17,726
|
|
1991
|
6,642
|
2,011
|
8,653
|
16,883
|
432
|
-
|
17,315
|
|
1992
|
6,090
|
1,991
|
8,081
|
17,088
|
418
|
-
|
17,506
|
|
1993
|
5,607
|
1,637
|
7,244
|
16,702
|
388
|
82
|
17,172
|
|
1994
|
5,644
|
1,417
|
7,061
|
15,662
|
330
|
670
|
16,662
|
|
1995
|
6,060
|
1,500
|
7,560
|
16,458
|
323
|
728
|
17,509
|
|
1996
|
6,139
|
1,435
|
7,574
|
17,298
|
332
|
595
|
18,225
|
|
1997
|
6,221
|
1,378
|
7,599
|
16,714
|
344
|
545
|
17,603
|
|
1998
|
5,855
|
1,203
|
7,058
|
14,997
|
301
|
273
|
15,571
|
|
1999
|
5,294
|
1,193
|
6,487
|
13,002
|
287
|
229
|
13,518
|
|
2000
|
4,413
|
1,015
|
5,428
|
12,037
|
255
|
243
|
12,535
|
|
2001
|
4,443
|
900
|
5,343
|
10,679
|
240
|
157
|
11,076
|
|
2002
|
|
