How long would you say you need to have your oldest account open to fall under the "Great" category of "length of credit history"? My oldest account is a credit card and this is showing to be 6 years and 11 months old.
YMMV. It varies per person based on their scoring bucket. For example, someone just starting out in credit with no negative accounts might see a "Great" indicator within the Length of History at a few years. Conversely, mine was "very Good" at 13 years with lots of accts reporting.