Each factories VIN (last 6 digits) generally started at 100001. Yes, there are exceptions to this rule. So subtract your last 6 from this number and it will tell you how many vehicles were produced from that specific factory (Hamtramck, St Louis, La. etc) of all lines. It can never tell you that you have the 100th '69 Road Runner as another factory (7th digit) may produce a RR and or GTX or Belve on the same line.
Technically you could have two or more cars with the same last 6 digits. but one digit of the VIN will be different.
