condition mean min max ZT0-3 42.5143147 36.95173561 48.07689379 ZT4-7 15.0654738825 13.095645484999999 17.03530228 ZT8-11 20.4015978775 15.82415732 24.979038435 ZT12-15 26.5343361625 26.065219685000002 27.00345264 ZT16-19 26.9487642 26.444936945000002 27.452591455 ZT20-23 28.1380942225 27.848259425000002 28.42792902