condition mean min max ZT0-3 2.12426 2.12426 2.12426 ZT4-7 1.7117749999999998 1.7117749999999998 1.7117749999999998 ZT8-11 1.45004 1.45004 1.45004 ZT12-15 2.46753 2.46753 2.46753 ZT16-19 2.05298 2.05298 2.05298 ZT20-23 1.970845 1.970845 1.970845