In the collapsible Histogram frame (shown below) you can turn on a histogram adjacent to the color bar using the Show Histogram toggle. You can also adjust the number of levels of the histogram by entering a new value into the Number of Levels text field.

The Export command allows you to output a Comma Separated Values (.csv) file containing each of the histogram ranges and the number of cells which fall into each range.

Examine Histogram
Use the options in the Histogram frame to turn on and customize the Histogram shown next to the Color Bar.