condition mean min max ZT0-3 9.6 9.6 9.6 ZT4-7 5.4 5.4 5.4 ZT8-11 40.900000000000006 40.900000000000006 40.900000000000006 ZT12-15 17.15 17.15 17.15 ZT16-19 19.85 19.85 19.85 ZT20-23 40.2 40.2 40.2