Details on the number of households qualified for social housing support in each local authority area are set out in the statutory Summary of Social Housing Assessments (SSHA). Since 2016, the Summary process has been carried out on an annual basis.
Below is the link to the summary report for 2018 which includes breakdowns by each local authority across a range of categories. Details on the length of time spent on the record of qualified households (waiting lists) can be found at tables 2.8 and A1.8 of the report.
It should be noted that the SSHA is a point in time exercise and does not necessarily reflect the dynamic nature of entry to and exit from the list.
My Department is currently finalising the 2019 summary with the Housing Agency and I expect to be in a position to publish the full detailed report shortly.