condition mean min max ZT0-3 15.7487 15.7487 15.7487 ZT4-7 13.43835 13.43835 13.43835 ZT8-11 15.72755 15.72755 15.72755 ZT12-15 14.84355 14.84355 14.84355 ZT16-19 16.4088 16.4088 16.4088 ZT20-23 15.1906 15.1906 15.1906