condition mean min max ZT0-3 8.371633333333333 5.359870000000001 13.46115 ZT4-7 20.800150000000002 20.800150000000002 20.800150000000002 ZT8-11 16.35555 16.35555 16.35555 ZT12-15 17.4404 14.18985 20.69095 ZT16-19 12.3021 12.3021 12.3021 ZT20-23 10.219545 10.219545 10.219545