Historical Rig Count
| Title |
|---|
|
1999 672.8 KB
|
|
1998 257.8 KB
|
|
1997 194.7 KB
|
|
1996 223.9 KB
|
|
1995 205.7 KB
|
|
1994 192.1 KB
|
|
1993 221.3 KB
|
|
1992 233.3 KB
|
|
1991 234.9 KB
|
|
1990 299.4 KB
|
|
1989 288.3 KB
|
|
1988 337.2 KB
|
|
1987 330.6 KB
|
|
1986 649.4 KB
|
|
1985 674.7 KB
|
|
1984 555.8 KB
|
|
1983 519.6 KB
|
|
1982 247.6 KB
|
|
1981 691.6 KB
|
|
1980 817.7 KB
|
|
1979 851.9 KB
|
|
1978 965.6 KB
|
|
1977 925.9 KB
|
|
1976 803.2 KB
|
|
1974 1.4 MB
|
|
1975 3.8 MB
|
|
1973 5.8 MB
|
|
1972 1.2 MB
|
|
1971 6.3 MB
|
|
1970 3.1 MB
|
|
1969 883.8 KB
|
|
1968 782.9 KB
|