First consider what you claim (perhaps you mean to make a different claim)
You are claiming that in some population x number of women get pregnant and a percentage of them get abortions legally. Then it becomes illegal and either the number of women getting pregnant increases and the percentage of them that want abortions goes up or the number of womean getting pregnant stays the same (or decreases) and the percentage of them that want abortions increases and also that larger percentage of woman wanting abortions produces a greater number of woman willing to break the law than were willing to get abortions when it was legal. I just dont see a way that making abortion illegal would increase the number of pregnant woman, or increase the percentage of woman that want abortions. The most it would likely do is shift some legal abortions to illegal ones which would predictably be a smaller number than the previous legal number.
In fact if one doubts that laws can decrease behavior then one is arguing that the existence of the state is a flawed concept. We don't need laws if they don't do what they are intended to do.
But to answer your question before roe v wade abortion in the US was very very rare (fractions of digits). Since roe v wade it has become very common (double digits). I think most of that increase was due to it becoming legal.
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