condition mean min max ZT0-3 8.424489999999999 7.511055 9.728885 ZT4-7 9.30816 9.30816 9.30816 ZT8-11 9.384429999999998 9.384429999999998 9.384429999999998 ZT12-15 11.2319675 10.954085 11.50985 ZT16-19 13.05395 13.05395 13.05395 ZT20-23 12.800149999999999 12.800149999999999 12.800149999999999