Fig. 1
From: Reference equations for spirometric indices from a sample of the general adult population in Nigeria
a-f Predicted mean and lower limit of normal (LLN) for FVC, FEV1, FEV ratio, PEFR, MMEF and MVV in males (height 170 cm) by age. FVC = forced vital capacity (Liters), FEV1 = forced expiratory volume in one second (Liters), FEV ratio = FEV1/FVC%, PEFR = peak expiratory flow rate(Liters/s), MMEF = maximal mid expiratory flow (Liters/s), MVV = maximal voluntary ventilation (Liters/min)