condition mean min max ZT0-3 9.7636675 9.226035 10.301300000000001 ZT4-7 9.25881 9.25881 9.25881 ZT8-11 8.780715 8.780715 8.780715 ZT12-15 0 0 0 ZT16-19 11.64205 11.64205 11.64205 ZT20-23 7.779310000000001 7.779310000000001 7.779310000000001