condition mean min max ZT0-3 20.929425000000002 19.7603 22.09855 ZT4-7 14.01845 14.01845 14.01845 ZT8-11 23.7708 23.7708 23.7708 ZT12-15 0 0 0 ZT16-19 25.63745 25.63745 25.63745 ZT20-23 23.8201 23.8201 23.8201