I don't think the virus is as well understood as you believe, which is why opening back up now may be premature.
Regardless, the riskiest pre-existing conditions appear to be obesity and hypertension. 57-75% of Americans are obese according to the dedicated Wikipedia page. Also bear in mind there is considerable variance among obesity rates per locale. What's the CFR in obese patients?
Edit: if you can't tell me the CFR in obese patients, you shouldn't be rushing to open everything back up. I don't know why people are silently downvoting but there is nothing incorrect or inconsistent about my comment and I'm just making a suggestion based on what little evidence exists.