There isn't a precise way of finding this information, the best option available is to use the Manager's Reports to see the number of a type of notebook items if you send SMS's as particular types.
On the main menu go to the Reports tab, then click on the reports Icon.
Click on the Managers Reports on the left hand side.
Click in the Managers Reports on the right hand side and press View.
Select the date range required, and consultants and under Selection Criteria select Get Notebook Note Type Numbers.
Select Output Grouped By Activity under Select the Reports and press Run.