I know the 1 piso coin changed composition from copper-nickel to nickel-plated steel in 2003, but were there any overlap years?
I've read that 2003 may have had both metal compositions, but I've never come across a nickel plated steel 2003 piso. I've seen other sources that have said that both types were produced until 2008, but I've also not seen any copper-nickel coins since 2003.