condition mean min max ZT0-3 8.262735 8.262735 8.262735 ZT4-7 10.382235 10.382235 10.382235 ZT8-11 10.48127 10.48127 10.48127 ZT12-15 7.824375 7.824375 7.824375 ZT16-19 10.71105 10.71105 10.71105 ZT20-23 10.869900000000001 10.869900000000001 10.869900000000001