well yes,if you get into other series, there are other districts in those years that have fewer then millions printed. I use the website i posted above for any question i might have, i found it to be very usefull!
This is an interesting way to collect currency with no premium paid to a dealer. Of course, I would only save better grade circulated notes. No rips, tears, ink stains etc. At worst..... You can always spend them for face value......It is not as if you could lose money in any way.....