condition mean min max ZT0-3 5.449999999999999 5.449999999999999 5.449999999999999 ZT4-7 3.5 3.5 3.5 ZT8-11 5.1 5.1 5.1 ZT12-15 7.2 7.2 7.2 ZT16-19 7.15 7.15 7.15 ZT20-23 7.45 7.45 7.45