Start by copying the list, and pasting it in another column. With the pasted data selected, click on menu option DATA> Remove Duplicates. This will allow you to have one column with all values, and one column with unique values only.
Copy data in a new column and apply Remove Duplicates
In the Remove Duplicates menu, make sure you have selected the right column, and uncheck in case there is no header
Remove Duplicates options
A confirmation message should be displayed, showing how many entries and unique values the list contains
Remove Duplicates operation result summary
Then, next to the first entry of the unique values, enter the following function, to count how many times it occurs in the full list
=countif([column with full list];[first value])
Creation of a countif formula on entries and values
See the first result, extend the formula to all unique values
Extension of the countif formula for all values
And voilà ! Here the result is displayed, with number of entries for each value
