condition mean min max ZT0-3 1.1160611666666667 0.2891385 1.694245 ZT4-7 0.36688849999999995 0.36688849999999995 0.36688849999999995 ZT8-11 1.1740285 1.1740285 1.1740285 ZT12-15 4.1390425 3.6786250000000003 4.5994600000000005 ZT16-19 3.422575 3.422575 3.422575 ZT20-23 2.9616249999999997 2.9616249999999997 2.9616249999999997