I have noticed the same thing with several sites that are number 1. I would say the numbers that Google show are inflated.
I like using the other Adwords tool: https://adwords.google.com/select/TrafficEstimatorSandbox- . What I do is put in $1000 for my daily budget and go from there. It gives you an idea of how many clicks a day you would get if you are near the top. It looks like your keywords should generate around 50 visits/clicks a day but that's about it.
Try to add and PWS=0 at the end of URL, to be sure, personal web search is disabled. If I have any good idea I will post, thx very much
Would you like to share the URL of your website? Or did you check it correctly that you are number one? If you're number one then you should get huge traffic.