Number of individuals in each measurement category
| Absolute FEV1 L | N | Absolute difference from predicted L | n | % pred | n | FEV1/FVC % | n |
| >4.50 | 204 | >0 | 1368 | >100.0 | 1371 | >85 | 842 |
| >4.25 | 138 | >−0.2 | 464 | >95.0 | 355 | >80 | 691 |
| >4.00 | 152 | >−0.4 | 312 | >90.0 | 313 | >75 | 566 |
| >3.75 | 187 | >−0.6 | 186 | >85.0 | 176 | >70 | 293 |
| >3.50 | 215 | >−0.8 | 119 | >80.0 | 137 | >65 | 112 |
| >3.25 | 281 | >−1.0 | 65 | >75.0 | 87 | >59 | 68 |
| >3.00 | 296 | >−1.4 | 56 | >70.0 | 60 | ≤59 | 61 |
| >2.75 | 269 | ≤−1.4 | 63 | >54.5 | 71 | ||
| >2.50 | 259 | ≤54.5 | 63 | ||||
| >2.25 | 225 | ||||||
| >2.00 | 155 | ||||||
| >1.75 | 125 | ||||||
| >1.40 | 67 | ||||||
| ≤1.40 | 60 |
FEV1: forced expiratory volume in one second
% pred: % predicted
FVC: forced vital capacity