condition mean min max ZT0-3 8.563201 8.563201 8.563201 ZT4-7 8.615343500000002 8.615343500000002 8.615343500000002 ZT8-11 8.23349 8.23349 8.23349 ZT12-15 9.5370015 9.5370015 9.5370015 ZT16-19 8.110198 8.110198 8.110198 ZT20-23 9.67205 9.67205 9.67205