The 1955-P Jefferson Nickel is one of the lower mintage coins in the series. It has a mintage of just over 8 million. Compare this to the mintage of the 1957-D, just a couple years later which has a mintage of over 136 million. Therefore, the 1955-P Nickel is a little tougher date.
Most 1955-P Jefferson Nickels were struck in poor quality. Uncirculated examples are scarce in MS66 condition, with probably no more than a couple hundred or less and that number might actually be less where there may even be less than 100 known.