condition mean min max ZT0-3 2.576285 2.576285 2.576285 ZT4-7 1.120955 1.120955 1.120955 ZT8-11 1.91045 1.91045 1.91045 ZT12-15 2.64812 2.64812 2.64812 ZT16-19 4.372215000000001 4.372215000000001 4.372215000000001 ZT20-23 2.765885 2.765885 2.765885