Summing lists of text in cells

Summing lists of text in cells

I have a column of text containing a list of school subjects, see below. I wish to sum how many time each word appears in the column so I can graph the results. I tried "countif" but couldn't get the search parameters right. Any suggestions? THanks, Bruce Gale

A1 history, English, math
A2 English, math
A3 history, math
A4 English, math

Totals:

History: 2
English: 3
Math: 4