| 1959 | 1982 | 1987 | 1992 | 1993 | 1994 | |
| Total revision | 0 | 17.6 | 42.3 | 82.9 | 75.9 | 70.3 |
| By source of revision | ||||||
| 0 | 17.6 | 42.3 | 82.9 | 75.9 | 70.3 | |
| By component | ||||||
| -.1 | 17.3 | 15.9 | 22.1 | 22.4 | 24.8 | |
| -.1 | 2.8 | 13.0 | -4.2 | -7.3 | -10.6 | |
| 0 | 5.2 | 9.6 | 2.8 | -1.9 | -5.9 | |
| 0 | 0 | 6.4 | -3.1 | -3.4 | -2.9 | |
| -.1 | -2.4 | -3.0 | -3.8 | -2.1 | -1.8 | |
| 0 | 14.5 | 2.9 | 26.3 | 29.7 | 35.4 | |
| 0 | 16.6 | 13.2 | 33.2 | 36.0 | 36.1 | |
| 0 | -2.1 | -10.3 | -6.9 | -6.3 | -.7 | |
| .2 | .3 | 26.4 | 60.7 | 53.6 | 45.4 | |
| 0 | 2.1 | 24.1 | 45.5 | 44.2 | 46.6 | |
| 0 | 0 | 7.1 | 8.8 | 12.2 | 14.7 | |
| 0 | -.7 | 1.6 | 1.4 | -1.0 | 1.7 | |
| .1 | -1.1 | -3.6 | 18.3 | 16.9 | 12.0 | |
| 0 | 0 | -2.7 | -13.3 | -18.9 | -29.7 | |