condition mean min max ZT0-3 9.707831 9.707831 9.707831 ZT4-7 10.732674 10.732674 10.732674 ZT8-11 9.829801 9.829801 9.829801 ZT12-15 9.557529 9.557529 9.557529 ZT16-19 9.0961045 9.0961045 9.0961045 ZT20-23 8.658068 8.658068 8.658068