| Value | Category | Cases | |
|---|---|---|---|
| 1 | Central heating system | 211 |
22.2%
|
| 2 | Electric heater | 1 |
0.1%
|
| 3 | Boiler | 21 |
2.2%
|
| 4 | Stove | 715 |
75.3%
|
| 6 | Other | 1 |
0.1%
|
| 9 | Missing | 0 |
0%
|
| Sysmiss | 51 |