An electronic board will be mass produced using a newly developed manufacturing process. The process was tested by producing 20 products, and the number of defects was counted on each board.

The following defect numbers were observed for these boards: 0, 1, 3, 2, 1, 2, 2, 2, 3, 4, 1, 0, 0, 1, 0, 2, 0, 0, 2, and 0. Plot the histogram and frequency diagrams for the number of defects.