condition mean min max ZT0-3 10.152307 10.152307 10.152307 ZT4-7 10.0274665 10.0274665 10.0274665 ZT8-11 9.714818000000001 9.714818000000001 9.714818000000001 ZT12-15 9.461442000000002 9.461442000000002 9.461442000000002 ZT16-19 9.5835455 9.5835455 9.5835455 ZT20-23 9.146932 9.146932 9.146932