Hi Steve,
On the assumption that you'd like the column headings to adjust based on the year that the statement is being printed for, this formula should accomplish what you're looking for:
=CONCATENATE(GLFPE("O","yyyy")," / ",GLFPE("OPEN","yyyy"))
There are lots of ways of doing this. This one was the first that sprang to mind.
If you'd like to force a line break between the years, use "\n" in the string concatenation.