condition mean min max ZT0-3 1.8496975 1.633275 2.0661199999999997 ZT4-7 0.689343 0.689343 0.689343 ZT8-11 0.5888415 0.5888415 0.5888415 ZT12-15 0 0 0 ZT16-19 1.04035 1.04035 1.04035 ZT20-23 1.470755 1.470755 1.470755