condition mean min max ZT0-3 38.907275 32.6084 45.20615 ZT4-7 38.75815 38.75815 38.75815 ZT8-11 55.8156 55.8156 55.8156 ZT12-15 0 0 0 ZT16-19 84.10419999999999 84.10419999999999 84.10419999999999 ZT20-23 59.2004 59.2004 59.2004