Insert number of rows based on cell values?

Column B contains geographical Areas. Column C contains a list of business departments.

North Env
North Env
North Ops
North Sales
North Sales
North Sales
South Env
South Maint
South Ops
South Sales
South Sales
South Sales

Etc.

The values and number of these departments will vary.

I want to insert lines to sum the totals at the bottom of each geographic area based on the number of different departments. So, for this example, for the North three lines would be inserted. For the South, 4 lines would be inserted.

Any ideas?