Each year volunteers count the number of breeding horseshoe crabs on the beaches of Delaware Bay every year; here are data from 2011 and 2012. The measurement variable is number of horseshoe crabs, one nominal variable is 2011 vs. 2012, and the other nominal variable is the name of the beach. Each beach has one pair of observations of the measurement variable, one from 2011 and one from 2012. The biological question is whether the number of horseshoe crabs has gone up or down between 2011 and 2012.Calculate the difference in breeding horseshoe crab populations by subtracting the 2012 count of horseshoe crabs for each beach from the 2011 horseshoe crab counts for the same beaches.