condition mean min max ZT0-3 13.718231 13.718231 13.718231 ZT4-7 13.1980995 13.1980995 13.1980995 ZT8-11 14.2280985 14.2280985 14.2280985 ZT12-15 13.303281 13.303281 13.303281 ZT16-19 13.600639999999999 13.600639999999999 13.600639999999999 ZT20-23 17.517184 17.517184 17.517184