condition mean min max ZT0-3 69.3 69.3 69.3 ZT4-7 68.4 68.4 68.4 ZT8-11 71.05000000000001 71.05000000000001 71.05000000000001 ZT12-15 69.9 69.9 69.9 ZT16-19 39.75 39.75 39.75 ZT20-23 79.45 79.45 79.45