condition mean min max ZT0-3 1.6 1.6 1.6 ZT4-7 2.5 2.5 2.5 ZT8-11 4.7 4.7 4.7 ZT12-15 5.449999999999999 5.449999999999999 5.449999999999999 ZT16-19 4.8 4.8 4.8 ZT20-23 2.7 2.7 2.7