Add additional historical game info

README.md

@@ -20,6 +20,16 @@ The first Powerball drawing was on April 22, 1992.
 The first Mega Millions drawing was on September 6, 1996.  The original name was "The Big Game" and was
 rebranded to Mega Millions in May 2002.
 
+However, each game has undergone rule changes that have altered the pool of numbers available for the main
+(white) balls and their respective game balls as well.  Due to this, the historical information used to 
+analyze the draws should start at the most recent rule change date.
+
+**The most recent change for Powerball was on October 4, 2015, when the main ball pool increased from 59 to 69
+numbers and the Powerball pool reduced from 35 to 26 numbers.**
+
+**The most recent change for Mega Millions was on April 5, 2025, when the Megaball ball pool was decreased from
+25 to 24 numbers as well as the addition of a 10x multiplier.**
+
 Historical results can be scraped from the web and added to the database from the URLs below.  The
 results must be scraped by year.  Changing the year in the URLs alters the resultset displayed.