Efforts to obtain data on a more frequent basis began again after the 1990 Census, when it became clear that the more burdensome long form was depressing overall census response rates and jeopardizing the accuracy of the count. At Congress's request, the Census Bureau developed and tested a new design to obtain long-form data. U.S. statistician Leslie Kish had introduced the concept of a rolling sample (or continuous measurement) design in 1981. This design featured ongoing, monthly data collection aggregated on a yearly basis, enabling annual data releases. By combining multiple years of this data, the Census Bureau could release "period" estimates to produce estimates for smaller areas. After a decade of testing, it launched as the American Community Survey in 2005, replacing the once-a-decade census long form.