How do inductions bias the due date statistics?

I wanted to make this simple data table after many visitors posed this question: We know that many women are induced for to avoid going postdate, doesn't this bias our data? After all, most of the graphs I have just throw out inductions and show data based on only spontaneous labor. But what if ALL those women who were induced were actually supposed to go late, how long would the real average pregnancy last? Most of the people asking this question believe in their hearts that the average baby wants to arrive closer to 41 weeks or later, and the medical field is in denial and wants to induce us for convenience. I do not believe this, but wanted a quick way to explain myself, so here's this page.

The problem with the "we're all meant to go 41 weeks" theory is that so many women spontaneously go into labor in the days leading up to 40 W, there aren't enough inductions (even in our induction-happy world) being done to offset the average. Here are the median days for the spontaneous labors (12137 total), and the shifted median if every induction (3720 total) was actually supposed to be a very late birth:

So basically, if all the induced women who took my survey had been left to stay pregnant until the very end (past 42 weeks), then the median day for birth would shift by 2 days. Not an entire week.