A botanist measured the heights, in centimeters, of 12 sunflower plants in a garden. The measurements are as follows:
185.2, 191.5, 178.9, 188.0, 190.1, 182.5, 193.3, 186.7, 179.4, 192.8, 180.6, 189.9
What is the range of the heights of these sunflower plants?