Stamp increases from the USPS by the numbers

They are more expensive yet again.

For third time in a year, the price of stamps on Sunday was increased by the United States Postal Service, this time going up from 63 cents to 66 cents.

It is the third time in a year that the price has gone up and also represents the 17th time since 2001 that the price of stamps has changed. In all but one of those 17 instances, the price went up.

The first price increase in that time frame went from 33 cents to 34 cents in 2001, meaning the cost of stamps has nearly doubled since.

Between 1952 and 1999, the price of stamps went up 14 times. Below is a closer look at when the price of stamps has changed since 2001 and by how much.