condition mean min max ZT0-3 392.473323 392.473323 392.473323 ZT4-7 264.1952035 264.1952035 264.1952035 ZT8-11 244.46060799999998 244.46060799999998 244.46060799999998 ZT12-15 283.65431 283.65431 283.65431 ZT16-19 427.2480865 427.2480865 427.2480865 ZT20-23 415.337177 415.337177 415.337177