A 9-year-old girl had an FVC of 2.35 L1 year ago. She was 122 cm (4 ft) tall and weighed 29.5 kg (65 lb). Her current height is 127 cm (4 ft 2 in), and her weight is
34 kg (75 lb). The current FVC measurement is 2.20 L. The quality of both tests met ATS/ERS goals. A pulmonary function technologist should conclude the change is