condition mean min max ZT0-3 4.55 4.55 4.55 ZT4-7 3.9 3.9 3.9 ZT8-11 17.05 17.05 17.05 ZT12-15 2.7 2.7 2.7 ZT16-19 11.600000000000001 11.600000000000001 11.600000000000001 ZT20-23 13.25 13.25 13.25