condition mean min max ZT0-3 5.699999999999999 5.699999999999999 5.699999999999999 ZT4-7 1.5 1.5 1.5 ZT8-11 5.2 5.2 5.2 ZT12-15 6.2 6.2 6.2 ZT16-19 2.7 2.7 2.7 ZT20-23 5.55 5.55 5.55