condition mean min max ZT0-3 190.687804 190.687804 190.687804 ZT4-7 202.0045265 202.0045265 202.0045265 ZT8-11 219.6185185 219.6185185 219.6185185 ZT12-15 243.87332600000002 243.87332600000002 243.87332600000002 ZT16-19 256.3456175 256.3456175 256.3456175 ZT20-23 257.430356 257.430356 257.430356