1900 census of Putnam Co., Indiana, Madison township, (undated), lists on p. 6B as family #123/123:
Evans, Oliver G., 31, b. Aug 1868, Ind Ind Ohio; Laura, wife, 35, b. July 1864, Ind Ind Ind, married 10 years, mother of 4 children, 4 living; Clarence, son, 9, b. Feb 1891; McKinley, son, 6, b. Oct 1893; Hollie, dau, 3, b. May 1897; Earle, son, 1, b. Jan 1899. All children born Ind Ind Ind.

Laura and Oliver had really only been married 4 years. Perhaps Oliver misinterpreted the question as being the number of years since his first marriage, and then the census taker just duplicated that number into Laura’s field.

1910 census of Sullivan Co., Indiana, Gill township, enumerated 20 April, lists on p. 10A as family #203/205:
Evans, Oliver G., farmer, 42, b. Ind Ind Ohio, second marriage; Laura E., wife, 46, b. Ind Ind Ind, first marriage, married 14 years, mother of 5 children, 5 living; Clarence Q., son, 19; MacKinley G., son, 16; Hallie E., dau, 12; Earl E., son, 11; Harry O., son, 8; Helen I., dau, 5; Lenora F., dau, 3. All children born Ind Ind Ind.

Putnam Co. Indiana marriage book 9, p. 248, records the marriage on 1 Mar 1896 of Oliver G. Evans and Laura E. Butler.