condition mean min max ZT0-3 508.897461 508.897461 508.897461 ZT4-7 83.323887 83.323887 83.323887 ZT8-11 77.341102 77.341102 77.341102 ZT12-15 115.0858835 115.0858835 115.0858835 ZT16-19 719.539749 719.539749 719.539749 ZT20-23 1256.0998215 1256.0998215 1256.0998215