c++ show data as graph in console

I want to display some values as a graph in a very mundane way on the console. My current output looks something like this:

                    9=========
                    2==
3===
8========
8========
                    3===
                    10==========
                    19===================
                    20====================
                    8========
                    0
7=======
3===
3===
3===

All the values on the left side are negative values and on the right side of the middle they are positive. The numbers also should stick all to the left side. I want the end result to look something like this:

9                    =========
2                    ==
-3                ===
-8           ========
-8           ========
3                     ===
10                    ==========
19                    ===================
20                    ====================
8                     ========
0                    
-7            =======
-3                ===
-3                ===
-3                ===

What do you think is the best way to accomplish this?