Homeownership rate from CPS data

When calculating the homeownership rate on the household level using household weights, I find very high homeownership rates pre 1985 (for example 68% in 1980) which are not in line with Census homeownership rate estimates (https://fred.stlouisfed.org/series/RH…). Do you have an idea, where this difference is coming from?

Homeownership rate calculated as

SUM[HWTSUPP(OWNERSHP == 10, YEAR == y, RELATE == 101)]/SUM[HWTSUPP(YEAR == y, RELATE == 101)]

The figures you are calculating use the CPS Annual Social and Economic Supplement (ASEC). The data shown in the FRED chart relies on the CPS Housing Vacancy Survey (HVS). There are differences in the housing unit estimates published in the HVS and ASEC. As noted by the Census: The ASEC is weighted to the population to describe characteristics of people living in households. The HVS is weighted to housing units, rather than the population, in order to more accurately estimate the number of occupied and vacant housing units. Because of the differences in weighting, estimates of the number of households in the ASEC and HVS do not match.

This is the aggregate quarterly data that it appears FRED is using.