condition mean min max ZT0-3 2.07985125 1.0873125 3.07239 ZT4-7 27.90435 27.90435 27.90435 ZT8-11 8.34761 8.34761 8.34761 ZT12-15 0 0 0 ZT16-19 7.691879999999999 7.691879999999999 7.691879999999999 ZT20-23 16.902 16.902 16.902