condition mean min max ZT0-3 1351.630741 1351.630741 1351.630741 ZT4-7 1397.771237 1397.771237 1397.771237 ZT8-11 1515.490937 1515.490937 1515.490937 ZT12-15 1538.5457585 1538.5457585 1538.5457585 ZT16-19 1298.3936804999998 1298.3936804999998 1298.3936804999998 ZT20-23 1205.5114045 1205.5114045 1205.5114045