condition mean min max ZT0-3 27.747003 27.747003 27.747003 ZT4-7 15.1398955 15.1398955 15.1398955 ZT8-11 14.262328499999999 14.262328499999999 14.262328499999999 ZT12-15 12.619335 12.619335 12.619335 ZT16-19 15.9354355 15.9354355 15.9354355 ZT20-23 24.645845 24.645845 24.645845