condition mean min max ZT0-3 11.466766666666667 7.3652 13.553450000000002 ZT4-7 7.124485 7.124485 7.124485 ZT8-11 13.859300000000001 13.859300000000001 13.859300000000001 ZT12-15 19.400725 13.0679 25.73355 ZT16-19 16.3567 16.3567 16.3567 ZT20-23 18.35765 18.35765 18.35765