condition mean min max ZT0-3 51.150000000000006 51.150000000000006 51.150000000000006 ZT4-7 20.9 20.9 20.9 ZT8-11 29.3 29.3 29.3 ZT12-15 37.0 37.0 37.0 ZT16-19 33.2 33.2 33.2 ZT20-23 43.85 43.85 43.85