condition mean min max ZT0-3 17.840355 17.840355 17.840355 ZT4-7 24.164754 24.164754 24.164754 ZT8-11 19.989199 19.989199 19.989199 ZT12-15 24.97904 24.97904 24.97904 ZT16-19 17.135865 17.135865 17.135865 ZT20-23 14.1454215 14.1454215 14.1454215