It also seems that the US's share of top companies is in decline with non-US countries' shares nearly doubling in that timeframe. I find it interesting to note

It also seems that the US's share of top companies is in decline with non-US countries' shares nearly doubling in that timeframe. I find it interesting to note how petroleum and financial companies now seems to be increasingly dominant. You could almost get the impression that the US has outsourced absolutely everything except harvesting oil and shoveling money around. Although I'm sure the picture is a little bit more nuanced than that (as you can see the same thing for other countries too) it does show an interesting trend and makes you wonder how this may turn out in the long run.