| 1996 | 1997 | 1998 | 1999 | 2000 | |
| JAN | -16.3 | -17.8 | -19.3 | -16.8 | |
| FEB | -14.1 | -15.6 | -9.4 | -12.9 | |
| MAR | -16.4 | -14.6 | -11.6 | 0 | |
| APR | -16.6 | -8.7 | -14.6 | -0.9 | |
| MAY | -4.7 | 0.0 | -6.6 | -6.9 | -2.9 |
| JUN | 1.9 | -1.7 | -0.4 | -3.4 | 3.3 |
| JUL | 3.4 | 3.6 | -2.9 | 5.6 | 5.0 |
| AUG | 2.2 | 5.8 | -0.5 | 5.0 | 1.8 |
| SEP | -3.5 | -0.6 | -5.8 | 1.3 | 2.8 |
| OCT | -11.7 | -11.8 | -14.2 | -4.6 | -11 |
| NOV | -14.9 | -12.6 | -12.9 | -8.7 | -13.8 |
| DEC | -13.7 | -19.7 | -19.8 | -12.1 | -10.8 |