condition mean min max ZT0-3 7.22658 7.22658 7.22658 ZT4-7 4.805365 4.805365 4.805365 ZT8-11 5.277615 5.277615 5.277615 ZT12-15 5.955095 5.955095 5.955095 ZT16-19 8.555879999999998 8.555879999999998 8.555879999999998 ZT20-23 8.241175 8.241175 8.241175