condition mean min max ZT0-3 4.0593200000000005 4.0593200000000005 4.0593200000000005 ZT4-7 5.551115 5.551115 5.551115 ZT8-11 4.893445 4.893445 4.893445 ZT12-15 3.072615 3.072615 3.072615 ZT16-19 2.36447 2.36447 2.36447 ZT20-23 4.268376666666667 4.268376666666667 4.268376666666667