Kindly assign a probability to each of the following being true (0-100%):

Intelligent extra-terrestrials have at some point visited earth - []

Intelligent extra-terrestrial life exists on earth - []

Intelligent extra-terrestrial life exists in the universe - []

Any extra-terrestrial life exists in the universe - []

Humans will discover concrete evidence of extra-terrestrial life this century - []

Humans will discover concrete evidence of intelligent extra-terrestrial life this century - []