In March 1965, an investigative study of property tax assessment practices published by the National Tax Association of 13,769 properties sold within the City of Boston from January 1, 1960 to March 31, 1964 found that the assessed values in the neighborhood of Roxbury in 1962 were at 68 percent of market values while the assessed values in West Roxbury were at 41 percent of market values, and the researchers could not find a nonracial explanation for the difference. Under the tenure of John F. Collins as Mayor of Boston (1960–1968), the Boston Housing Authority segregated the public housing developments in the city as well, moving black families into the development at Columbia Point while reserving developments in South Boston for white families who started refusing assignment to the Columbia Point project by the early 1960s. In 1962, upon receipt of a lawsuit filed by a civil rights group, the West Broadway Housing Development was desegregated after having been designated by the city for white-only occupancy since 1941. In the same year, the Mission Hill project had 1,024 families (all white), while the Mission Hill Extension project across the street had 580 families (of which 500 were black), and in 1967 when the city government agreed to desegregate the developments, the projects were still 97 percent white and 98 percent black respectively.