Scott 2015 Standard Postage Stamp Catalogue Volume 6: Countries of the World San-Z (Scott Standard Postage Stamp Catalogue Vol 6 San-Z)

More than 10,000 value changes were made in Volume 6, which includes countries of the world from San Marino through Zululand. In general, the market remains stable, with classic issues and stamps from the last decade rising in value.
There were a large number of changes for several African nations - Somalia and Swaziland had almost 800 each. There was also extensive activity in South America with 1,550 value changes in Venezuela and more than 1,300 in Vanuatu.