So I guess it's roughly analogous to ROTJ's gap (Which was kind of a weird one, as the group took a whole year to go to Tatooine despite already planning the rendevous? Although the old "Shadows of the Empire" EU storyline, as well as the old Marvel comics, explained the big delay).
So pretty much (episodes only):
TPM to AOTC: 10 years
AOTC to ROTS: 3 years
ROTS to ANH: 18 years
ANH to ESB: 3 years
ESB To ROTJ: 1 year
ROTJ to TFA: 30 years
TFA to TLJ: Hours at most
TLJ to 9: 1 year