condition mean min max ZT0-3 4.912660000000001 4.4114 5.41392 ZT4-7 2.7871449999999998 2.7871449999999998 2.7871449999999998 ZT8-11 3.15966 3.15966 3.15966 ZT12-15 0 0 0 ZT16-19 3.83096 3.83096 3.83096 ZT20-23 4.3032 4.3032 4.3032