condition mean min max ZT0-3 192.455286 192.455286 192.455286 ZT4-7 198.6385535 198.6385535 198.6385535 ZT8-11 205.04328800000002 205.04328800000002 205.04328800000002 ZT12-15 191.91251 191.91251 191.91251 ZT16-19 244.5214165 244.5214165 244.5214165 ZT20-23 228.797536 228.797536 228.797536