Once you acquire the data (legally), here is how experts use the 1901-2000 volume:

– Spanning the entire 20th century (1901–2000), this volume covers an era of immense change: two world wars, the end of colonialism, the rise and fall of the Soviet Union, and the transition from silver/gold standards to base metal and clad coinage. The 2018 edition includes late-20th-century commemoratives and circulation issues that earlier catalogs miss.