Finding time of last pg_stat_reset

I'm trying to figure out if there's any way to find when statistics was 
last reset. Previously when we were using 8.2, we had 
stats_reset_on_server_start set to on, and then assumed 
pg_stat_get_backend_start as the start time for collected stats. Is 
there any way to do this in 8.3, without f.ex adding a call to 
pg_stat_reset() in our startup scripts?

-- 
Tommy Gildseth