Fuel usage for a 1999 1HZJ 75 series Troopy

I've not long returned from a 7.5 week road trip from Perth to Townsville and return driving my 24 year old Troopy. This is a bog standard vehicle with no turbo and minimal upgrade to the suspension and wearing Cooper ST Maxx tyres.
I went via the Great Central Road and had to go up to Tennant Creek and into Qld via the Barkly Highway as the Plenty Highway was closed at that stage. I visited locations like Boulia, Winton, Longreach and Emerald for family history reasons before heading up to Townsville to meet my better half who had flown over. After going down the coast to Brisbane, we spent some time visiting locations like St George, Glenmorgan, Surat, Charleville and Cunnamulla again for family history reasons. Then down through Bourke, Cobar, Wilcannia and Port Augusta before heading across the Nullarbor to home.
Total distance - 12,882km
Total litres of diesel - 1,704.2
Total cost of diesel - $3,539
Average fuel usage - 13.22l/100km
Average cost - $27.47/100km
Most expensive fuel was at the Warburton Roadhouse. Average speed was in the range of 95 - 105kmh although slower on the GCC.
Had an oil and filters change at the Toyota dealer in Townsville. Only issues were the oil pressure gauge stopped working outside Camooweal and the bonnet release cable broke south of Cunnamulla. One small windscreen chip.
The lesson for me was that a well maintained vehicle will generally get you where you want to go.