Salary gap in the sciences—is this fair?

http://www.the-scientist.com/Nov2014/11_14_SalarySurveyforWeb.pdf

Comparing salary information gathered in May 2008 to the most recent BLS data collected in May 2013, Saranna Thornton, an economist at Hampden–Sydney College in Virginia and chair of the committee on the Economic Status of the Profession at the American Association of University Professors (AAUP), found that while positions in chemistry, physics, and computer science received pay increases of 8.3 percent to 10.6 percent over the five-year period, the life sciences saw the smallest increases. Industry biochemists and biophysicists received just a 3.6 percent increase over the same time and those in the academic biological sciences a mere 4.6 percent. The Scientist, Nov. 1, 2014.