condition mean min max ZT0-3 3.904991666666667 3.1939900000000003 4.31216 ZT4-7 7.73869 7.73869 7.73869 ZT8-11 25.973599999999998 25.973599999999998 25.973599999999998 ZT12-15 25.73415 23.16165 28.306649999999998 ZT16-19 14.99595 14.99595 14.99595 ZT20-23 8.164045 8.164045 8.164045