| 1996 | 1997 | 1998 | 1999 | 2000 | |
| JAN | -4.6 | -3.5 | -2.6 | -0.9 | |
| FEB | -3.6 | -5.9 | 0.3 | -0.8 | |
| MAR | 1.2 | -3.4 | -0.1 | 4.0 | |
| APR | 0.2 | 2.4 | -0.5 | 7.4 | |
| MAY | 8.6 | 7.3 | 6.2 | 6.4 | 9.8 |
| JUN | 12.6 | 10.1 | 12.4 | 10.2 | 11.1 |
| JUL | 12.2 | 11.4 | 10.4 | 10.4 | 12.5 |
| AUG | 10.9 | 11.4 | 10.8 | 11.1 | 11.3 |
| SEP | 7.1 | 10.5 | 7.7 | 9.4 | 11.0 |
| OCT | 3.1 | 2.8 | 4.3 | 6.4 | 3.3 |
| NOV | 0.0 | -0.5 | 0.8 | 4.0 | -3.5 |
| DEC | -2.0 | -6.5 | -3.1 | -3.3 | -1.0 |