condition mean min max ZT0-3 9.681291666666667 4.490925 12.90565 ZT4-7 5.384415000000001 5.384415000000001 5.384415000000001 ZT8-11 5.359585 5.359585 5.359585 ZT12-15 7.7205475 6.751935 8.689160000000001 ZT16-19 8.7091 8.7091 8.7091 ZT20-23 13.0704 13.0704 13.0704