The estimate from 100 years ago was 1.2 million a year, so clearly the number of abortions.  Per capita numbers are declining and the change in numbers reported likely have to do with measurement effects due to illegality (as well as some doctors who performed abortions did  so claiming miscarriage - now I suspect that modern technology has women going in for abortion and finding out that the fetus was already dead anyway).  Regardless, the question is how to enforce any ban you would enact, or the lack of detail your side proposes (and how what some propose is unworkable - like saying you can call it murder and not prosecute mothers and that legal personhood would not have an effect on the legal status of all first trimester embryos, including the miscarried).