We provide two sets of historical data on belief in angels: one relating to belief in angels (1995-2009), graphed below; and one relating to belief in Guardian angels specifically (1998-2009).
Belief in angels, 1995-2009: click here to download the data.
Belief in guardian angels, 1998-2009: click here to download the data.
Dear Deborah BRIN has not looked into this, but I am hopeful that you may be able to find this…