condition mean min max ZT0-3 12.736933 12.736933 12.736933 ZT4-7 12.8757635 12.8757635 12.8757635 ZT8-11 13.1561995 13.1561995 13.1561995 ZT12-15 13.351184499999999 13.351184499999999 13.351184499999999 ZT16-19 11.051395 11.051395 11.051395 ZT20-23 15.038826 15.038826 15.038826