condition mean min max ZT0-3 10.897995 10.897995 10.897995 ZT4-7 8.65075 8.65075 8.65075 ZT8-11 8.771475 8.771475 8.771475 ZT12-15 9.55586 9.55586 9.55586 ZT16-19 14.210550000000001 14.210550000000001 14.210550000000001 ZT20-23 10.99685 10.99685 10.99685