condition mean min max ZT0-3 10.770785 7.646755000000001 12.5106 ZT4-7 6.27855 6.27855 6.27855 ZT8-11 3.830615 3.830615 3.830615 ZT12-15 6.485155000000001 6.357715 6.612595000000001 ZT16-19 6.82676 6.82676 6.82676 ZT20-23 11.28905 11.28905 11.28905