Here is a simple query for Upvotes & Downvotes on Questions & Answers. I filtered it down to August 1st, 2013 to August 1st, 2014.

We're definitely voting more and, generally speaking, upvotes dwarf downvotes. We downvote questions more often than answers.

I'm not sure if that's good or bad, but I wanted to add it here for the conversation. Feel free to update this with new results or improved queries.