Previous estimates of eta-Earth suggest that 15-25% of stars host potentially habitable planets. These estimates are based largely on discoveries of planets orbiting the cooler stars called M dwarfs. These new discoveries suggest that the statistics for sun-like stars are roughly in-line with estimates from the cooler M-type stars. So how does that translate to the number of planets in the galaxy? M, K, and G dwarfs comprise about 90% of the stars in the galaxy. Conservatively speaking, if 15% of stars have a planet between 1 and 1.6 times the size of Earth in the Habitable Zone, then you'd expect 15% of 90% of 100 billion stars to have such planets. That's 14 billion potentially habitable worlds.

M type stars are the most common in the galaxy comprising about 70% of the population of Main Sequence stars. Here's how the star types break down for the solar neighborhood within 33 light-years:

357 stars total

248 of those are M dwarfs

44 K dwarfs

20 G dwarfs

That means "only" about a billion of the 14 billion I mentioned above are orbiting G stars. Ha!