Let me just remind everyone of this again:
This survey considers the period of time after President Obama was elected and the Dems strengthened their hold on Congress. It represents a reaction by those who were worried that guns would become harder to get. Of course, over that period, States were citizens were not already well-armed would show the greatest reaction in the form of buying guns.
This, in terms of gun-buying, is called The Obama Effect. Look it up.