This is just a list of people who are registered as "dead" with the Social Security Administration (filtered for "Ewing" surname and Arizona's SSN) since 1980. This means it has no marriage status, or maiden names for that matter, or even gender information, but it has the birthdate (5th column), given name (3rd column) and middle name initial if any (4th column). The dates are in GEDCOM format.
In particular, the list has three Williams:
William Ewing, born 06 Jan 1907, died Apr 1979.
William C. Ewing, born 27 Mar 1919, died 21 Apr 2009
William P. Ewing, born 12 Oct 1932, died 19 Mar 2000
There's also a "W. N. Ewing" (note: this could be a woman!), born 20 Jul 1909, died 01 Jan 1997.
... as well as 73 other dead people with that family name.
The base Death Master File contains an estimated 75% of all deaths in the USA from 1962 on, with the latter years being the most accurate, up to 95% of all deaths which occured in the 21st century.