condition mean min max ZT0-3 162.797234 162.797234 162.797234 ZT4-7 379.674539 379.674539 379.674539 ZT8-11 309.6767245 309.6767245 309.6767245 ZT12-15 197.136605 197.136605 197.136605 ZT16-19 142.92470500000002 142.92470500000002 142.92470500000002 ZT20-23 173.2773755 173.2773755 173.2773755