Bongo Fury

I know that this questions has been asked 1000 times. but reading the post everyone gives a different measure

I have a 97 bongo with air con in the front and back (dual system?) how much r134a do I need?

The air con is not cold enough and we are in Italy now with 38c outside.

Thanks

950g seems to be the figure to go for with 14ml of pag46 oil.