At the top of your Overview, Social, Sales, Marketing, Radio and TV dashboards you will see an orange date range in the Navigation Bar next to the Reports button.
Click on this to expand the date selector - you can pick a date range from the right-hand side, or apply a custom date range using the fields on the left to view data for dates of your choice.
Doing this will update the data available in your timelines. It will also show you figures in big number modules for the selected time period. Any growth figures will be against the previous equivalent period.
For example, if you choose to look at the last month of data, you will see the total figure for that month, the difference against the previous month, a lifetime total and finally your growth percentage against the month prior.