As of June 30, 2020, the Registry has 9,805 twin pairs (19,610 individuals). New pairs are enrolled on a quarterly basis. Below is a detailed breakdown of the Twin Registry population, calculated from the survey that twins complete when they join the Registry.

Age

Age group	% at enrollment	% today
9 and younger	5.2	4.3
10-19	20.2	2.1
20-29	19.2	10.5
30-39	14.3	28.2
40-49	11.9	15.8
50-59	12.4	13.4
60-69	11.2	13.4
70+	5.7	12.2

Ethnicity
Hispanic/Latino: 4.0%

Race
One race: 96.9%
White: 90.0%
Black or African American: 2.0%
American Indian or Alaska Native: 0.6%
Asian: 2.5%
Native Hawaiian or Other Pacific Islander: 0.4%
Some other race: 1.4%
Two or more races: 3.1%
White and Black or African American: 0.5%
White and American Indian or Alaska Native: 0.8%
White and Asian: 0.8%
Two or more other races: 1.0%

Zygosity
Identical: 53.0%
Fraternal: 47.0%

Sex
Male/Male pairs: 28.4%
Female/Female pairs: 49.9%
Male/Female pairs: 21.7%

Zygosity/Sex
MZ Male pairs: 19.1%
MZ Female pairs: 34.0%
DZ Male pairs: 9.4%
DZ Female pairs: 16.0%
DZ Male/Female pairs: 21.7%

Where are our members located?