condition mean min max ZT0-3 30.784075 29.1112 32.45695 ZT4-7 38.7492 38.7492 38.7492 ZT8-11 19.517400000000002 19.517400000000002 19.517400000000002 ZT12-15 0 0 0 ZT16-19 19.082349999999998 19.082349999999998 19.082349999999998 ZT20-23 34.505250000000004 34.505250000000004 34.505250000000004