prescription dispensing among a cohort

[Sharan]

I'd like to find out prescription dispensing among a cohort of children between say 2000- 2005. I'd like to know the number dispensed in first 10 years. for those born in 200o, they will be aged 10 years in 2010, but for those born in 2005, they will be aged 10 in 2015.  I don't not want the 2011 prescriptions for those born in 2000 to appear in this data. Anyone? 

[ballardw]

Some example data would be helpful. For example, how do we know ages in a year? Does the data have birth date/year? Date of "dispensing"? Your description may not be using a standard definition of age. Someone born 1 July 2005 is not 10 years old in January 2015, and would still be 10 years old in June of 2016.