condition mean min max ZT0-3 28.963601 28.963601 28.963601 ZT4-7 29.5744695 29.5744695 29.5744695 ZT8-11 32.3408035 32.3408035 32.3408035 ZT12-15 26.3179815 26.3179815 26.3179815 ZT16-19 30.006625999999997 30.006625999999997 30.006625999999997 ZT20-23 29.310575999999998 29.310575999999998 29.310575999999998