I don't know why you or someone else found it necessary to remove my response, it suggested (Are you English Challenged?), that of course to your inane question "Can you prove it?" was already responded to in the post that provoked your diatribe, you just do not comprehend what you read. As your post quoted mine, I'll repeat the part of the post you apparently failed to comprehend specifically my post already stated I don't and certainly cannot prove that that is indeed what has happened last year (in the class period),, so unless you failed to understand what I wrote, why ask again "can you prove it" if I already stated I cannot? Thus "English Challenged".