My 200gpd membranes are nearly two years old and the water goes in at 385 and comes out at 13/16ppm (until recently it was between 9 and 12 so I think they are getting "tired".)
Then the water goes through the DI and it is 000ppm for about about 800 litres of usable water. It rises to 001 for the next 800L or so and then I get about 400L at 002ppm at which point I change the resin (750ml).
I don't have a resin bottle on the van and at the brush I get about 002/005.