The source of the statistic:

The Ukeles team poses the question: “Is today’s generation of
young American Jews distinctive?” But most interesting is their observation that this age cohort is
significantly differentiated among themselves. They find that Orthodox young adults and non-Orthodox married couples with children differ substantially in patterns of Jewish belief and behavior from non-Orthodox singles and married but childless couples and intermarried couples, with or without children....

They also observe that the growing percentage of the age cohorts that are Orthodox (16 percent for the 18-29 age group as compared with 9 percent of the 30-39 group) portends an increasingly Orthodox population in the Jewish community of the future.

Read the rest of the survey here. Ken yirbu.