condition mean min max ZT0-3 15.760925 12.83005 18.6918 ZT4-7 6.538095 6.538095 6.538095 ZT8-11 17.577199999999998 17.577199999999998 17.577199999999998 ZT12-15 0 0 0 ZT16-19 16.63435 16.63435 16.63435 ZT20-23 13.283100000000001 13.283100000000001 13.283100000000001