condition mean min max ZT0-3 8.957717500000001 6.726485 11.18895 ZT4-7 8.02692 8.02692 8.02692 ZT8-11 9.275054999999998 9.275054999999998 9.275054999999998 ZT12-15 0 0 0 ZT16-19 10.52215 10.52215 10.52215 ZT20-23 12.26465 12.26465 12.26465