condition mean min max ZT0-3 17.24701 17.24701 17.24701 ZT4-7 17.67729 17.67729 17.67729 ZT8-11 16.570347 16.570347 16.570347 ZT12-15 12.833698 12.833698 12.833698 ZT16-19 13.855671000000001 13.855671000000001 13.855671000000001 ZT20-23 14.5703195 14.5703195 14.5703195