Value |
Category |
1 |
Very easy |
2 |
Easy |
3 |
Uncertain |
4 |
Difficult |
5 |
Very difficult |
9 |
|
13 |
|
99 |
|
0 |
NR |
Sysmiss |
|
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.