condition mean min max ZT0-3 19.926762 19.926762 19.926762 ZT4-7 16.394896499999998 16.394896499999998 16.394896499999998 ZT8-11 16.4339415 16.4339415 16.4339415 ZT12-15 18.3374635 18.3374635 18.3374635 ZT16-19 15.057663999999999 15.057663999999999 15.057663999999999 ZT20-23 13.681203 13.681203 13.681203