| Value | Category |
|---|---|
| 0 | Absent |
| 1 | Slight and infrequently present |
| 2 | Mild in amplitude and persistent; or moderate in amplitude, but only intermittently present |
| 3 | Moderate in amplitude and present most of the time |
| 4 | Marked in amplitude and present most of the time |
| 8 | Untestable |