condition mean min max ZT0-3 10.603583 10.603583 10.603583 ZT4-7 10.3641005 10.3641005 10.3641005 ZT8-11 12.3243005 12.3243005 12.3243005 ZT12-15 11.251634 11.251634 11.251634 ZT16-19 11.882817500000002 11.882817500000002 11.882817500000002 ZT20-23 9.6629365 9.6629365 9.6629365