I have a list of lists that looks like this:
You can do something along the following lines (I could not test as I have no such structure):
extract.year <- function(my.year) lapply(x, function(y) y[[my.year]]) x.by.year <- sapply(my.list.of.years, function(my.year) do.call(rbind, extract.year(my.year)))
The function extract year creates a list containing just the dataframes for the given year. Then you rbind them...