condition mean min max ZT0-3 28.843619 28.843619 28.843619 ZT4-7 11.312446000000001 11.312446000000001 11.312446000000001 ZT8-11 13.3123765 13.3123765 13.3123765 ZT12-15 17.4182645 17.4182645 17.4182645 ZT16-19 18.527439 18.527439 18.527439 ZT20-23 16.3122005 16.3122005 16.3122005