| Value |
Category |
| 1 |
Every day |
| 2 |
Very often (5-6 times) |
| 3 |
Some days (1-4 nights) |
| 4 |
Not used at all |
| 5 |
Never used |
| 99 |
Don't know |
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.