| Survey year | Male | Female | ||||
| 16–44 | 45–74 | 75 and over | 16–44 | 45–74 | 75 and over | |
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | |
| 1995 | ||||||
| Number | 2879 | 2527 | 409 | 3216 | 2833 | 564 |
| FEV1 (litres) | 4.30 (0.72) | 3.09 (0.87) | 2.13 (0.63) | 3.16 (0.52) | 2.24 (0.60) | 1.44 (0.45) |
| FEV1/FVC (%) | 82 (8) | 75 (11) | 71 (12) | 84 (8) | 78 (10) | 75 (11) |
| 1996 | ||||||
| Number | 2931 | 2686 | 421 | 3326 | 3007 | 598 |
| FEV1 (litres) | 4.32 (0.72) | 3.17 (0.87) | 2.12 (0.64) | 3.17 (0.52) | 2.29 (0.61) | 1.47 (0.4) |
| FEV1/FVC (%) | 82 (8) | 76 (10) | 71 (12) | 84 (8) | 79 (9) | 76 (11) |
| 1997 | ||||||
| Number | 1577 | 1428 | 203 | 1746 | 1574 | 301 |
| FEV1 (litres) | 4.33 (0.74) | 3.18 (0.84) | 2.13 (0.70) | 3.17 (0.52) | 2.31 (0.61) | 1.50 (0.48) |
| FEV1/FVC (%) | 83 (8) | 77 (11) | 71 (13) | 84 (8) | 79 (9) | 76 (12) |
| 2001 | ||||||
| Number | 2256 | 2365 | 364 | 2614 | 2662 | 488 |
| FEV1 (litres) | 4.30 (0.75) | 3.19 (0.85) | 2.13 (0.65) | 3.14 (0.54) | 2.32 (0.59) | 1.48 (0.45) |
| FEV1/FVC (%) | 83 (8) | 78 (11) | 73 (12) | 85 (8) | 80 (9) | 76 (11) |
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.