condition mean min max ZT0-3 20.700000000000003 20.700000000000003 20.700000000000003 ZT4-7 8.8 8.8 8.8 ZT8-11 38.1 38.1 38.1 ZT12-15 48.15 48.15 48.15 ZT16-19 57.5 57.5 57.5 ZT20-23 41.5 41.5 41.5