condition mean min max ZT0-3 3.955115 3.53362 4.37661 ZT4-7 2.187585 2.187585 2.187585 ZT8-11 3.859915 3.859915 3.859915 ZT12-15 0 0 0 ZT16-19 5.505425 5.505425 5.505425 ZT20-23 5.274185 5.274185 5.274185