condition mean min max ZT0-3 5.5270775 5.44979 5.604365 ZT4-7 4.276375 4.276375 4.276375 ZT8-11 10.75225 10.75225 10.75225 ZT12-15 0 0 0 ZT16-19 18.09085 18.09085 18.09085 ZT20-23 8.271115 8.271115 8.271115