condition mean min max ZT0-3 10.300036666666667 9.121210000000001 11.4667 ZT4-7 8.391825 8.391825 8.391825 ZT8-11 7.9628250000000005 7.9628250000000005 7.9628250000000005 ZT12-15 13.21845 12.11905 14.31785 ZT16-19 13.7421 13.7421 13.7421 ZT20-23 12.6371 12.6371 12.6371