condition mean min max ZT0-3 1.1966447 0.0 1.9511716 ZT4-7 0.0 0.0 0.0 ZT8-11 3.174055 3.174055 3.174055 ZT12-15 3.276305 1.57279 4.97982 ZT16-19 0.0 0.0 0.0 ZT20-23 1.2855555 1.2855555 1.2855555