condition mean min max ZT0-3 20.095097 20.095097 20.095097 ZT4-7 19.0443115 19.0443115 19.0443115 ZT8-11 20.7796285 20.7796285 20.7796285 ZT12-15 19.141236499999998 19.141236499999998 19.141236499999998 ZT16-19 22.5693645 22.5693645 22.5693645 ZT20-23 19.0922885 19.0922885 19.0922885