| 1996 | 1997 | 1998 | 1999 | 2000 | |
| JAN | -15.7 | -10.5 | -14.0 | -14.9 | |
| FEB | -11.9 | -13.1 | -11.7 | ||
| MAR | -14.3 | -12.1 | -11.3 | -14.7 | |
| APR | -14.6 | -11.7 | -13.0 | -8.8 | |
| MAY | -2.4 | 1.6 | -4.5 | -4.3 | -1.9 |
| JUN | 3.2 | 2.4 | 4.9 | -1.9 | 4.8 |
| JUL | 7.8 | 6.5 | 6.0 | 6.7 | 6.6 |
| AUG | 7.7 | 7.1 | 6.6 | 6.8 | 2.9 |
| SEP | 0.2 | 3.6 | 4.9 | 3.7 | 3.8 |
| OCT | -10.3 | -3.0 | -2.1 | -9.7 | |
| NOV | -12.1 | -11.0 | -8.6 | -14.7 | |
| DEC | -11.7 | -15.8 | -11.2 | -10.2 |