<< Graphics`Graphics`


countdata  = {12, 14, 18, 18, 19, 20, 21, 22, 22, 22, 29, 30, 32, 
          32, 34, 36, 37, 41, 43, 44, 45, 46, 51, 53, 54, 54, 55, 55, 55, 57, 
          57, 58, 61, 62, 62, 64, 64, 65, 65, 65, 67, 68, 68, 68, 69, 70, 71, 
          73, 74, 74, 74, 74, 75, 77, 77, 77, 79, 80, 80, 81, 82, 82, 83, 83, 
          87, 87, 88, 89, 89, 90, 91, 92, 93, 95, 95, 95, 95, 95, 95, 95, 95, 
          96, 97, 98, 98, 98, 100, 101, 102, 104, 109, 110, 110, 
          110};

Histogram[countdata, 
      HistogramCategories -> {0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 
          100,  110,  120}]

less50  = 
        Select[countdata,  (# < 50)  &];
Length[less50]

fifty2sixty  =  
        Select[countdata, ( (# < 60) &&  (#  ≥  
                    50)) &];
Length[fifty2sixty]

sixty2seventy =  
        Select[countdata, ( (# < 70) &&  (#  ≥  
                    60)) &];
Length[sixty2seventy]

seventy2eighty =  
        Select[countdata, ( (# < 80) &&  (#  ≥  
                    70)) &];
Length[seventy2eighty]

eighty2ninety =  
        Select[countdata, ( (# < 90) &&  (#  ≥  
                    80)) &];
Length[eighty2ninety]

greater90  =  
        Select[countdata,  (# ≥  
                90) &];
Length[greater90]