It is quite hard to me to say about the circulating steem. I even didn't know that respective number of sbd with respect to steem price is counted as steem supply. This post is too informative. There is big difference between your analysis and coinmarket or coingecko. I don't kno whether this two site is recently updated or not. Steem is being produced at every moment. So the supply is changing rapidly.

There can be also some mistake or any technical issues. Anyway Thanks a lot for this post.