Problem: How to count occurances in an array and divide it with the total number of figures, formatted as percent?

Solution:

=COUNTIF($A$1:$A$20,A1)/COUNTA($A$1:$A$20)

COUNTIF(range,criteria)
Counts the number of cells within a range that meet the given condition

COUNTA(value1,[value2],)
Counts the number of cells in a range that are not empty