Johanna graphed the number of calls she made during one day. How many calls were made before 6 p.m.?

A histogram titled Cell Phone Calls has time of day on the x-axis and number of calls on the y-axis. From 10 to 12 pm there were 2 calls; from 12 to 2 pm there were 8 calls; from 2 to 4 pm there were 0 calls; from 4 to 6 pm there were 10 calls; from 6 to 8 there were 4 calls; from 8 to 10 pm there were 2 calls.