condition mean min max ZT0-3 25.028213 25.028213 25.028213 ZT4-7 21.28515 21.28515 21.28515 ZT8-11 21.8593895 21.8593895 21.8593895 ZT12-15 24.2130655 24.2130655 24.2130655 ZT16-19 21.148259000000003 21.148259000000003 21.148259000000003 ZT20-23 18.620699000000002 18.620699000000002 18.620699000000002