condition mean min max ZT0-3 2.25 2.25 2.25 ZT4-7 5.5 5.5 5.5 ZT8-11 7.1499999999999995 7.1499999999999995 7.1499999999999995 ZT12-15 3.7 3.7 3.7 ZT16-19 6.1499999999999995 6.1499999999999995 6.1499999999999995 ZT20-23 2.6500000000000004 2.6500000000000004 2.6500000000000004