condition mean min max ZT0-3 4.777635 4.39528 5.1599900000000005 ZT4-7 6.884395 6.884395 6.884395 ZT8-11 6.990545 6.990545 6.990545 ZT12-15 0 0 0 ZT16-19 7.8905199999999995 7.8905199999999995 7.8905199999999995 ZT20-23 6.984615 6.984615 6.984615