| 1996 | 1997 | 1998 | 1999 | 2000 | |
| JAN | -3.2 | -1.6 | -0.9 | -0.1 | |
| FEB | -2.6 | 0.9 | 0.4 | ||
| MAR | 2.6 | -2.0 | 2.0 | 0.8 | |
| APR | 3.0 | 0.0 | 2.5 | 7.6 | |
| MAY | 13.0 | 11.0 | 8.8 | 9.8 | 13.6 |
| JUN | 16.0 | 14.2 | 17.7 | 13.3 | 14.2 |
| JUL | 15.2 | 14.9 | 14.6 | 12.4 | 15.1 |
| AUG | 13.8 | 13.3 | 13.4 | 13.4 | 13.3 |
| SEP | 9.8 | 12.4 | 12.8 | 11.3 | 13.1 |
| OCT | 5.3 | 6.7 | 7.3 | 4.9 | |
| NOV | 1.3 | 1.9 | 4.3 | -2.5 | |
| DEC | -0.5 | -1.3 | -2.2 | -0.6 |