| Estimate | Peaks | ||||
| 1969:III | 1973:IV | 1980:I | 1981:I | 1990:II | |
| Advance | x | x | x | x | y |
| Preliminary | x | x | x | x | y |
| Final | (/1/) | (/1/) | x | x | y |
| First annual | x | (/1/) | (/1/) | (/1/) | y |
| Second annual | x | x | x | y | x |
| Third annual | x | x | x | x | x |
| Troughs | |||||
| 1970:IV | 1975:I | 1980:III | 1982:III | 1991:I | |
| Advance | x | y | y | y | x |
| Preliminary | x | x | y | y | x |
| Final | (/1/) | (/1/) | y | y | x |
| First annual | x | x | (/1/) | y | x |
| Second annual | x | x | y | x | x |
| Third annual | x | x | y | (/1/) | x |
1. Estimate was not made.
x Peak or trough correctly identified
y Peak or trough not correctly identified