| Graphical Method | # (%) of Papers | # of Figures |
| (a) Basic visual methods | ||
| Bar chart | 17 (46%) | 37 |
| Line/Point/Area chart | 18 (49%) | 22 |
| Pie/Donut chart | 12 (32%) | 21 |
| (b) Extended visual methods | ||
| Histogram | 1 (3%) | 2 |
| World map | 8 (22%) | 9 |
| Heatmap | 1 (3%) | 2 |
| Scatter plot | 7 (19%) | 7 |
| Parallel plot | 1 (3%) | 1 |
| Dendrogram | 1 (3%) | 1 |
| Hilbert-curve | 1 (3%) | 1 |