score:7
The probable reason why you are asked if you lived at your current residence for 5 years is to run an approriate background check. If you answer "no", you will be asked for all your residences you've lived at for the past 5 years.
Part of the TSA Precheck program application is a background check:
... approved travelers are issued a Known Traveler Number (KTN) after completing a TSA background check and screening.
A background check can include a compilation of criminal records, in the USA this is obtained from the town police services.
So in order to check you have not done anything bad in your past, the TSA will likely contact the police in all areas you have lived an check your criminal records. This also means that for those who have lived in multiple towns over the past 5 years, their application might take a little longer.
In your case, unless you want to hide anything, you can probably apply mentioning your two places of residence over the past 5 years.
Upvote:2
As indicated above, They want to know all places of residence for the last 5 years to do a background check. Personal experience: For a number of reasons I lived in 6 places during last 5 years, and I just got approved.