condition mean min max ZT0-3 2.1948725 2.097045 2.2927 ZT4-7 1.3287565000000001 1.3287565000000001 1.3287565000000001 ZT8-11 1.2471800000000002 1.2471800000000002 1.2471800000000002 ZT12-15 0 0 0 ZT16-19 4.009145 4.009145 4.009145 ZT20-23 2.1838550000000003 2.1838550000000003 2.1838550000000003