condition mean min max ZT0-3 16.923693 16.923693 16.923693 ZT4-7 17.3680045 17.3680045 17.3680045 ZT8-11 16.1317785 16.1317785 16.1317785 ZT12-15 14.04082 14.04082 14.04082 ZT16-19 19.3150645 19.3150645 19.3150645 ZT20-23 17.597169 17.597169 17.597169