ECSENOMICS Appropriable Natural Resources Are S Declining Relative to Economy T-133 igure 18-5 Fi Total. all marketed natural resources 10 5 Other resource sectors* 1940 1950 1960 1970 1980 1990 2000 Year McGraw-Hilllrwin Source: U.S. Commerce Department.McGraw-Hill/Irwin Copyright © 2001 The McGraw-Hill Companies, Inc. All rights reserved. Appropriable Natural Resources Are Declining Relative to Economy T-133 Figure 18-5 Source: U.S. Commerce Department