condition mean min max ZT0-3 13.1 13.1 13.1 ZT4-7 5.4 5.4 5.4 ZT8-11 7.949999999999999 7.949999999999999 7.949999999999999 ZT12-15 1.7999999999999998 1.7999999999999998 1.7999999999999998 ZT16-19 26.4 26.4 26.4 ZT20-23 9.75 9.75 9.75