I had a 10 yr. search done for my ggrandmother's death cert. Unfortunately, nothing came up. I KNOW she died! I KNOW she never moved from Philadelphia. NEVER. THe time frame was 1918-1928. Either her death was not recorded(?) or the person searching failed to see her cert. So we are really at the mercy of the people searching. I had this happen with a birth cert. I knew my mother was born in Phil. and when they came up blank for a birth cert. in 1926, I called them on the phone and asked them to please search again...lo and behold, there was the birth. cert. I guess the only way to be certain is to do the search yourself if possible. I am sure these workers are over-burdened.