In the nineties and noughties it was probably about the same as it had always been before. A couple of bumper years, followed by several years of drought (sex life can also be like that!).
But it does seem that the drought periods are increasing and the good years perhaps gone forever. The steady erosion of GA can be blamed on- in no particular order:
1. too many companies chasing too little business, cutting prices and consequently snivelling on pilot conditions to try and balance their books - this has always been a problem, but is now the worst it's ever been with pilots sometimes expected to pay for their own IR renewals even though they are employed
2. too many pilots prepared to work for nothing and, as above, actually pay for the privilege
3. 40 year old aircraft which are no longer economic to maintain properly and are no longer acceptable to corporate clients; yet there are no affordable replacements - when the latest Baron sells for over a million bucks, who will pay for that?
4. cheap airfares, reasonable services to most regional airports now and much improved vehicles to get to those airports
So why would anyone charter some clapped-out old GA heap at whatever exorbitant rate per seat (compared with the airlines) when their trusty Landcruiser can deliver them in airconditioned comfort to an airport where a Q 400 or ATR 72 awaits? Not too many GA aircraft even have air conditioning.
In nearly 50 years at the game, I never saw a sustained pilot shortage, whether at GA level or in the airlines. There was a time in the U.K. where the high cost of entry meant they experienced a shortage for a few years, but that is certainly no longer the case there. Here, any shortage typically only lasted about year at a time. No, I do not believe we will ever see a pilot shortage hereabouts. China, yes, the USA maybe, Australia, never.
Move on, requalify in something that will enable you to find a well paid job and as suggested above, buy a nice RA machine if you really must fly.