condition mean min max ZT0-3 19.506375 19.208 19.80475 ZT4-7 14.8369 14.8369 14.8369 ZT8-11 11.8916 11.8916 11.8916 ZT12-15 0 0 0 ZT16-19 22.265900000000002 22.265900000000002 22.265900000000002 ZT20-23 22.017400000000002 22.017400000000002 22.017400000000002