From The Atlantic:

22 percent—essentially one in five—of sun-like stars have
potentially habitable Earth-size planets. (Not all of those planets,
however, may be rocky or feature liquid water, a presumed prerequisite
for life. And it’s worth noting, as well, that the margin of error for
that stat is plus or minus 8 percent.) Caveats aside, however, that is
still an astoundingly large number.