11. Every score in the following batch of exam scores is in the 60 s, 70 s, 80 s, or 90 s. A stem-and-leaf display with only the four stems 6, 7, 8, and 9 would not give a very detailed description of the distribution of scores. In such situations, it is desirable to use repeated stems. Here we could repeat the stem 6 twice, using 6L for scores in the low 60 s (leaves 0, 1, 2, 3, and 4) and 6H for scores in the high 60 s (leaves 5, 6, 7, 8, and 9). Similarly, the other stems can be repeated twice to obtain a display consisting of eight rows.

Construct such a display for the given scores. What feature of the data is highlighted by this display?
74 89 80 93 64 67 72 70 66 85 89 81 81 71 74 82 85 63 72 81 81 95 84 81 80 70 69 66 60 83 85 98 84 68 90 82 69 72 87 88