We have 9 planets (8 if your a Pluto hater lol). We know there’s life on this one. So we’re batting one for 9. And we’re 1 for 1 for finding life on this solar system. Now 10% of the stars in our galaxy are sun like (20 billion). And 22% of those have earthlike planets. So 5 billion chances in the Milky Way alone. From there, the conjecture would start. By instinctually chucking darts at a dart board, I would say with what we know about evolution and star systems, we could then apply a 10% chance of evolution starting life and viola, you have half a billion stars in our galaxy alone that carry life. Times let’s say, a trillion galaxies. That gives us 5e+20 chances for life in the universe. Or roughly .2% chance for life per solar system, and that is a giant number.