Those are unusual categories for income. The first three correspond reasonably well to the three lowest quintiles so each would have about 20% of the population. The 75 K is a little high for the third quintile (65 K would be better), and adds about an additional 5% or more to the sample there. If that were the only issue, I wouldn't have much to quibble about.
However, If I wanted equal numbers of people in each data point, the next cut shouldn't be at 150 K. That leaves only about 5% of the population in the uppermost bin and about 30% in the next to highest bin. The cut should be at about 100 K, so it's not close to a balanced sample. The effect is that any attempt to draw conclusions from the slope of the line at the high-income side will be skewed by the shift of population from the top data point into the next-to-top point.