Looking at the article again, that may be a fair interpretation. The Pew Research Center's article[0] from which one of the graphs is lifted says "white men are

Looking at the article again, that may be a fair interpretation. The Pew Research Center's article[0] from which one of the graphs is lifted says "white men are often used in comparisons such as this because they are the largest demographic group in the workforce". So the point of comparison seems to be on the basis of the size of the demographic rather than availability of past data. It also notes a possible reason for the gap: among adults ages 25 and older, 53% of Asians have a bachelor’s degree or more versus only 36% of whites. [0]: http://www.pewresearch.org/fact-tank/2016/07/01/racial-gender-wage-gaps-persist-in-u-s-despite-some-progress/ http://www.pewresearch.org/fact-tank/2016/07/01/racial-gende...