condition mean min max ZT0-3 4.55 4.55 4.55 ZT4-7 1.8 1.8 1.8 ZT8-11 2.1500000000000004 2.1500000000000004 2.1500000000000004 ZT12-15 4.35 4.35 4.35 ZT16-19 8.200000000000001 8.200000000000001 8.200000000000001 ZT20-23 3.05 3.05 3.05