Allow users to customize the X-axis intervals shown in a Van Westendorp plot (price sensitivity meter). Currently, there is some control by using the minimum/maximum value settings, but it can sometimes alter the data shown. For example, if a user has data points that go up to 6,000,000, the intervals show in 1,000,000 increments by default. Allow users to show smaller increments of their choosing, such as 100,000 or even 10,000.