condition mean min max ZT0-3 0.5367333333333333 0.43590249999999997 0.689422 ZT4-7 0.5048520000000001 0.5048520000000001 0.5048520000000001 ZT8-11 0.4780385 0.4780385 0.4780385 ZT12-15 0.5396265 0.537598 0.541655 ZT16-19 0.546481 0.546481 0.546481 ZT20-23 0.6182835 0.6182835 0.6182835