| Value |
Category |
| 2 |
MAIN SOURCE |
| 3 |
WHEN MAIN SOURCE OUT OF SERVICE |
| 4 |
TO SUPLEMENT MAIN SOURCE |
| 6 |
other |
| 9 |
UN/DA |
| 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.