condition mean min max ZT0-3 31.971850000000003 31.971850000000003 31.971850000000003 ZT4-7 39.341849999999994 39.341849999999994 39.341849999999994 ZT8-11 27.94715 27.94715 27.94715 ZT12-15 15.5456 15.5456 15.5456 ZT16-19 20.763849999999998 20.763849999999998 20.763849999999998 ZT20-23 22.3037 22.3037 22.3037