Make it a point to define how many years of data your enterprise search engine should retrieve. For example, if you typically store records for seven years for tax compliance, then you might define the years based on that specific number.
On the other hand, if you only perform data searches for two or three years back, proceed to configure your system accordingly. The longer back the search needs to go, the more robust your system will need to be, and the more expensive it will be to maintain.