$hash = (
   'FILE_MINUTE_2' => { 1 => {ID=1, COUNT_1 = 10, COUNT_2 = 20},
                        2 => {ID=2, COUNT_1 = 10, COUNT_2 = undef},
                        3 => {ID=3, COUNT_1 = undef, COUNT_2 = 20},
                        4 => {ID=4, COUNT_1 = 10, COUNT_2 = 20},
                      },
                      

);