I have composed a spreadsheet that includes a column that attributes a grade to each row/item: 1,2,3 or 4.
I need to find a formula that will allow me to display a total for each grade, in overall percentage terms, i.e.:

(column)
.. 4 .......... (cell) 4=30%
.. 4 .......... (cell) 3=20%
.. 4 .......... (cell) 2=20%
.. 3 .......... (cell) 1=30%
.. 3 ..........
...2
...2
..1
..1
..1

thanks for taking the time to read this.