Your monthly rate will also increase by 72%.
For example, if your utility bill for the year is $168 and it increases by 72% to $288.96, and you were paying $14 a month, this will rise to $24.08, which is a 72% rise in the monthly payment.
Note that this assumes that there is no additional charge for paying the bill monthly rather than annually. The percentage of the utility bill you pay each month does not depend on the percentage increase in the utility charge: it’s always going to be a twelfth (8.3%) of the annual charge. Some utility companies discount the one-off annual payment, so that monthly payments are higher than one twelfth of the annual charge. But there is no more information in the question about this, so the assumption stands.