MOT History VOSA Check - Buying a car

[amo]

Hi, I hope I have put this on the right bit.....bit of advice please? I am looking at buying a car and I checked the MOT history on VOSA; they are only showing MOT records for last two years? I have no idea why, the car is over 20 years old and I have just done a HPI check and it is all clear. Maybe been off the road? Seems strange.