condition mean min max ZT0-3 4.4621525 4.277995 4.64631 ZT4-7 8.129325 8.129325 8.129325 ZT8-11 3.01954 3.01954 3.01954 ZT12-15 0 0 0 ZT16-19 5.4625 5.4625 5.4625 ZT20-23 2.959285 2.959285 2.959285