condition mean min max ZT0-3 2.7857525 2.15983 3.411675 ZT4-7 1.9297405 1.9297405 1.9297405 ZT8-11 4.326905 4.326905 4.326905 ZT12-15 0 0 0 ZT16-19 4.885425 4.885425 4.885425 ZT20-23 5.992290000000001 5.992290000000001 5.992290000000001