I have a huge spreadsheet with simple data as follows
13:04:28 A
13:04:37 A
13:06:56 B
13:07:03 B
13:07:10 C
13:07:18 C
13:07:23 C
13:07:28 C
13:07:33 C
Basically timestamp,classification in two columns. i want to plot a pie chart showing the distribution of A,B and C etc by the number of times of their occurrence. How can I do so?