condition mean min max ZT0-3 2.329765 2.329765 2.329765 ZT4-7 1.58083 1.58083 1.58083 ZT8-11 2.0309749999999998 2.0309749999999998 2.0309749999999998 ZT12-15 2.47471 2.47471 2.47471 ZT16-19 3.1460600000000003 3.1460600000000003 3.1460600000000003 ZT20-23 2.297045 2.297045 2.297045