condition mean min max ZT0-3 4.50342 4.50342 4.50342 ZT4-7 3.9455 3.9455 3.9455 ZT8-11 3.23204 3.23204 3.23204 ZT12-15 2.934085 2.934085 2.934085 ZT16-19 3.584645 3.584645 3.584645 ZT20-23 3.1422600000000003 3.1422600000000003 3.1422600000000003