I use graph combine to combine multiple graphs in two columns and I would like to have two different centered titles at the beginning of each column. Does anyone have an idea how to achieve that? I tried different title options but they are always centered in the middle.

graph combine gr1.gph gr2.gph gr3.gph gr5.gph gr6.gph gr7.gph, cols(2)
Title 1 Title 2
graph 1 graph 4
graph 2 graph 5
graph 3 graph 6