To answer the question: What are the chances of survival of individual chess pieces in average games?
https://www.quora.com/What-are-the-chances-of-survival-of-individual-chess-pieces-in-average-games
You will need to convert your database to extended long-algebraic (-Welalg) format with pgn-extract first. (Make sure to also strip out variations, comments, annotations, or anything else that could confuse the very simplistic parser)
Databases are available from various places on the internet including http://www.top-5000.nl/pgn.htm
GLHF.