People aged over 75 accounted for more than three-quarters (79.3%) of all Covid-19 related deaths in Northern Ireland.
Nisra figures record all deaths where Covid-19 is mentioned on a death certificate.
The data covers up to last Friday, when there were 1,518 deaths due to COVID-19 in Ireland.
There are now 615 people hospitalised with coronavirus and 72 care home outbreaks, recorded on the department's dashboard breakdown.
Most (32) occurred in care homes, which represents a drop from 38 the previous week and 72 in the week before.
Nisra publishes weekly statistics which total all deaths where coronavirus has been recorded on the death certificate.
Thirty-three deaths happened at residential addresses or another location.
That's also the case for confirmed cases - in this region, one person in every 346 has been diagnosed with COVID-19.
Professor Philip Nolan, Chair of the NPHET Irish Epidemiological Modelling Advisory Group, said; "Most indicators continue to improve, with ICU and hospital admissions, number of cases per day and number of deaths per day continuing to decline".
According to the latest figures from the Health and Safety Authority (HSA), the number of overall workplace inspections that have been carried out this week stands at 400 - among which meat plants are included.
Homes accounted for nearly half of the 664 Covid-19 deaths recorded by Nisra up to May 15.
The total death toll is ultimately set to be higher.
The five-year average death rate in Northern Ireland is 295.
According to Nisra statistics, the highest number of deaths have been recorded in the Belfast council area with a total of 196 fatalities.
In the week up to 15 May, there were both a total of 322 male and 330 female coronavirus related deaths.
It also captures the deaths caused indirectly by the epidemic: people who died because of the strain on hospitals and care homes or people affected by the lockdown.