condition mean min max ZT0-3 13.303216666666668 12.663 13.824950000000001 ZT4-7 17.7214 17.7214 17.7214 ZT8-11 20.402900000000002 20.402900000000002 20.402900000000002 ZT12-15 21.634225 20.702399999999997 22.56605 ZT16-19 17.18665 17.18665 17.18665 ZT20-23 17.773899999999998 17.773899999999998 17.773899999999998