| Value | Category | Cases | |
|---|---|---|---|
| 1 | Central heating system | 1590 |
15.8%
|
| 2 | Electric heater | 23 |
0.2%
|
| 3 | Boiler | 368 |
3.6%
|
| 4 | Stove | 8095 |
80.2%
|
| 6 | Other | 8 |
0.1%
|
| 9 | Missing | 8 |
0.1%
|
| Sysmiss | 408 |