| Value |
Category |
| 1 |
DIFF LEVER,SAME PROGRAM,DIFF SPEED |
| 2 |
ALL STD SAME LEVEL |
| 3 |
DIFF LEVEL,DIFF PROGRAM |
| 9 |
OMITTED |
| 11 |
.A |
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.