How do you calculate change in concentration of a specific subset of a population?

I am trying to figure out the change in concentration of a specific population. For example, in 2000 there were 1,870 students 58 students were a minority. In 2006 there were 2,192 and 83 were a minority. What is the change in concentration of minority students. I know the percent change (new value – old)/old; but I am trying to figure out if the concentration has increased b/c the total population has increased.