Java Histogram Help

[alice.cooper.18659]

I am trying to make a histogram that represent the number of letter grades that are calculated. So the program reads in a csv file, pulls out the name, average grade and letter grade. From there it creates a histogram based on the letter Grades.

Input:

Alicia Marks,89,90,100,95,75,85,94,100,90,92
Bobby Ricks,98,79,87,79,9,98,7,19,98,78

How output should look like:

Alicia Marks 85.5 B
Bobby Ricks 90.0 A-

A: 1
A-: 1
B+: 2
B: 3
B-: 5
C+: 7
C: 0
C-: 0
D+: 4
D: 0
F: 1

import java.io.File;
import java.io.FileNotFoundException;
import java.util.*;
import java.lang.*;

public class Grades {

        public static void main(String[] args) {
        Grades x = new Grades();
        System.out.println("");
        x.histo();
        }

        public void histo() {
        File file3 = new File("scores.csv");

        String letter;
        double sumNumber = 0.0;
        ArrayList<Double> avg = new ArrayList<>();
        ArrayList<String> letterGrade = new ArrayList<>();

    try {
        Scanner scanner = new Scanner(file3);
         while (scanner.hasNextLine()) {
            String lines = scanner.nextLine();
            String[] values = lines.split(",");

    // Converts String Array into Double Array
        double[] score = new double[values.length - 1];
        for (int i = 1; i < values.length; i++) {
            score[i - 1] = Double.parseDouble(values[i]);
        }

   // Finds the sum and then the average, adds it to a array List
        double sumNum = 0.0;
        for (double i : score) {
            sumNum += i;
        }
        double aver = sumNum / 10;
        avg.add(aver);

        String letterG;
        if( aver < 0.0)
            letterG = "F";
        else if(aver < 60.0)
            letterG = "D";
        else if(aver < 67.0)
            letterG = "D+";
        else if(aver < 70.0)
            letterG = "C-";
        else if(aver < 73.0)
            letterG = "C";
        else if(aver < 77.0)
            letterG = "C+";
        else if(aver < 80.0)
            letterG = "B-";
        else if(aver < 83.0)
            letterG = "B";
        else if(aver < 87.0)
            letterG = "B+";
        else if(aver < 90.0)
            letterG = "A-";
        else 
            letterG = "A";  

        letterGrade.add(letterG); 
        }   //WL


        for(int i = 0; i < letterGrade.size(); i++) {
            letterGrade.get(i);
            String theLetter = letterGrade.get(i);
            int current = 1;
        if (letterGrade.contains(theLetter)){
            int j = current++;
            System.out.println(theLetter + "\t" + j);
            }
        else
            System.out.println(theLetter + "\t" + "0");
            }


    } catch (FileNotFoundException e) { 
            e.printStackTrace();
        }

    } //Histo End
} // Class End

So, I can make somewhat of a histogram, but I can't figure out how to get the blank values. So when B has no value, how do I get that to implement. I am also trying to figure out how to replace the numeric values with stars, so that it looks like this

A : *
A-: *
B+: **
B : ***

So any help in fixing this is super appreciated.