condition mean min max ZT0-3 19.707875 19.393250000000002 20.0225 ZT4-7 18.762999999999998 18.762999999999998 18.762999999999998 ZT8-11 19.3988 19.3988 19.3988 ZT12-15 0 0 0 ZT16-19 24.367649999999998 24.367649999999998 24.367649999999998 ZT20-23 24.5306 24.5306 24.5306