S30 Ngram Key Terms

Exemplar

Exemplar

Social 20-1 Terms ranged in three different ways (each color is one of 4 related issues)

RI1 RI2 RI3 RI4

1600 1700 1800 1850 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2015

environmental social economic political