condition mean min max ZT0-3 17.655475000000003 15.891200000000001 19.41975 ZT4-7 14.239550000000001 14.239550000000001 14.239550000000001 ZT8-11 12.835550000000001 12.835550000000001 12.835550000000001 ZT12-15 0 0 0 ZT16-19 19.82185 19.82185 19.82185 ZT20-23 20.21885 20.21885 20.21885