I FOUND IT!!!!!
Burried in section 1, almost a footnote, the real numbers….
“One other common definition should be mentioned: In traditional Jewish law (halakha), Jewish identity is transmitted by matrilineal descent. The survey finds that 87% of adult Jews by religion and 70% of Jews of no religion – a total of about 4.8 million U.S. adults – say they had a Jewish mother. Additionally, about 1.3 million people who are not classified as Jews in this report (47% of non-Jews of Jewish background) say they had a Jewish mother.”