condition mean min max ZT0-3 2.25 2.25 2.25 ZT4-7 1.5 1.5 1.5 ZT8-11 13.75 13.75 13.75 ZT12-15 4.6499999999999995 4.6499999999999995 4.6499999999999995 ZT16-19 15.700000000000001 15.700000000000001 15.700000000000001 ZT20-23 2.0 2.0 2.0