condition mean min max ZT0-3 15.9 15.9 15.9 ZT4-7 76.8 76.8 76.8 ZT8-11 63.800000000000004 63.800000000000004 63.800000000000004 ZT12-15 53.95 53.95 53.95 ZT16-19 47.6 47.6 47.6 ZT20-23 20.65 20.65 20.65