condition mean min max ZT0-3 3.5945825 2.19149 4.997675 ZT4-7 8.28285 8.28285 8.28285 ZT8-11 7.803945000000001 7.803945000000001 7.803945000000001 ZT12-15 0 0 0 ZT16-19 11.201654999999999 11.201654999999999 11.201654999999999 ZT20-23 10.00471 10.00471 10.00471