Fair point on 2015 being pretty recent - I have dug back as far as I could find which is only to 2005 - so we are still missing the 80s / 90s but this is what we have to work with. I have a vague memory of old White Dwarf surveys that covered what people were playing? Anyone who could point to those - that would be great.

So - from 50 icv2.com retailer surveys back to 2004 of "Top Five Roleplaying Games" we get:
Dungeons & Dragons 48
Pathfinder 31
World of Darkness 23
Dark Heresy/Rogue Trader 20
Star Wars (FFG) 18
Shadowrun 17
Fantasy/Dragon Age 11
Exalted 8
Mutants & Masterminds 7
WHFRP 2E (BI/GR) 7
Starfinder 5
Iron Kingdoms 5
Fate Core System 4
Mongoose (Traveller?) 4
WHFRP 3E (FFG) 4
Green Ronin** 3
GURPS 3
Scion 3
Alien 2
Cyberpunk 2
Mutants and Masterminds, inc. DC 2
Numenera 2
Song of Ice and Fire 2
Star Wars (WotC) 2
Adventures in Middle Earth 1
Call of Cthulhu 7th Edition 1
Genesys (FFG) 1
Legend of the Five Rings (FFG) 1
Star Trek Adventures 1
Fate 1
Battlestar Galactica 1
BESM 1
Dresden Files 1
Dungeon Crawl Classics 1
Marvel Heroic Roleplaying 1
The One Ring 1

The notable change is there was a Mongoose (assume Traveller?) moment back in 2005.

So thats the data - my story says there wasn't a lot of it around when we were playing back in the 90s. If it wasn't fantasy it was X-files or Matrix inspired 'shades and trench-coats' stuff - either Shadowrun, Con-X or a fairly splatter-fest take on WoD - all the sci-fi stuff was on the wargame tables as Battletech or 40k. I knew some guys who ran a long-running Star Wars campaign, there were a few stand-out LARPs on the con circuit but that was it. If you were throwing dice at a table it was lots and lots of D&D and L5R, maybe WoD or Shadowrun.

Anyone any ideas why our screens are full of sci-fi - so obviously people have time for it - but not our tables?