condition mean min max ZT0-3 5.2 5.2 5.2 ZT4-7 3.6 3.6 3.6 ZT8-11 9.85 9.85 9.85 ZT12-15 6.6000000000000005 6.6000000000000005 6.6000000000000005 ZT16-19 5.85 5.85 5.85 ZT20-23 4.9 4.9 4.9