I love the idea, the simple design, and the humble tone of the byline ("no one knows for sure, but there are indicators that can help us guess. We can chart these indicators to give us the illusion of foresight.").

However, I have two suggestions. First, the numeric rankings (such as "5.5 / 10") need context: why not say something like "10 is the highest value reached in the historical record"?

Second, the explanations you give for chosing these indicators need a bit of work, as evidenced by some of the comments and questions on this thread. Most lay readers won't understand why the ratio of total stock market capitalization to annual GDP is important.