condition mean min max ZT0-3 4.145765 4.070465 4.221064999999999 ZT4-7 5.772735 5.772735 5.772735 ZT8-11 9.185045 9.185045 9.185045 ZT12-15 0 0 0 ZT16-19 9.910685 9.910685 9.910685 ZT20-23 6.997635 6.997635 6.997635