condition mean min max ZT0-3 0.545051 0.41747 0.6871735 ZT4-7 0.2661115 0.2661115 0.2661115 ZT8-11 0.616503 0.616503 0.616503 ZT12-15 0.8549955 0.5482535 1.1617375 ZT16-19 0.8019069999999999 0.8019069999999999 0.8019069999999999 ZT20-23 0.67524 0.67524 0.67524