To be able to do such a report (in either FTM 16 or FTM2012) supposes that you know whether everyone in your file is alive or dead, and if alive, when they were born. Most people won't have that information for everyone in their file.
If you do, that's great; except that you won't be able to get this report out of FTM2012. The Custom Report in FTM will put the following in a custom report:
Age at first marriage
Age at first child
Age at last child
Age at death
But, I don't find where one can use age at the date the report is run (or any other selected date) to determine age.
You probably could make a custom report and export birth and death dates and calculate an age in Excel. You could also use the "Index of Individuals Report" and sort out living and calc an age in Excel.
If you do have a file with all of this information, it is probably a pretty small file. In that case, you could create a custom fact and input their ages and include that Fact in a custom report.