condition mean min max ZT0-3 5.569640000000001 5.569640000000001 5.569640000000001 ZT4-7 2.7976099999999997 2.7976099999999997 2.7976099999999997 ZT8-11 4.386645 4.386645 4.386645 ZT12-15 7.34769 7.34769 7.34769 ZT16-19 6.25391 6.25391 6.25391 ZT20-23 4.911816666666667 4.911816666666667 4.911816666666667