condition mean min max ZT0-3 3.5705216666666666 2.26787 4.415095 ZT4-7 1.76165 1.76165 1.76165 ZT8-11 2.52797 2.52797 2.52797 ZT12-15 3.78855 3.418735 4.158365 ZT16-19 4.32179 4.32179 4.32179 ZT20-23 5.1974350000000005 5.1974350000000005 5.1974350000000005