English: This graph shows the income of the given percentiles plus the average from 1947 to 2010 in 2010 dollars. The 2 columns of numbers in the right margin are the cumulative growth 1970-2010 and the annual growth rate over that period. The vertical scale is logarithmic, which makes constant percentage growth appear as a straight line. From 1947 to 1970, all percentiles grew at essentially the same rate; the light, straight lines for the different percentiles for those years all have the same slope. Since then, there has been substantial divergence, with different percentiles of the income distribution growing at different rates. For the median American family, this gap is $39,000 per year (just over $100 per day): If the economic growth during this period had been broadly shared as it was from 1947 to 1970, the median household income would have been $39,000 per year higher than it was in 2010. The median was computed as the geometric mean of the 40th and 60th percentiles. Those two quantiles and the 20th percentile came from US Census Bureau Table F-1.^[1] The 99th, 99.9th, and 99.99th percentiles were computed from US Internal Revenue Service data by Piketty and Saez.^[2] There are systematic differences between these two sources, but the differences are small relative to the scale of this plot.^[3]