condition mean min max ZT0-3 7.656599999999999 6.764575 8.548625 ZT4-7 14.5601 14.5601 14.5601 ZT8-11 12.55111 12.55111 12.55111 ZT12-15 0 0 0 ZT16-19 15.2037 15.2037 15.2037 ZT20-23 16.22325 16.22325 16.22325