condition mean min max ZT0-3 2.32324 2.32324 2.32324 ZT4-7 1.4950999999999999 1.4950999999999999 1.4950999999999999 ZT8-11 1.77765 1.77765 1.77765 ZT12-15 1.8441450000000001 1.8441450000000001 1.8441450000000001 ZT16-19 2.18621 2.18621 2.18621 ZT20-23 1.59123 1.59123 1.59123