Since the Covid-19 pandemic began, there have been a total of 1,375 deaths linked to the virus in this country. 

Each day, we wait to hear an update on additional reported deaths and newly diagnosed cases from the Chief Medical Officer, to update the overall picture of how much of a grip this deadly virus has on our country. 

But it is also useful to compare the overall numbers of people who have died in recent months, from Covid-19 or otherwise, to the average number of deaths we would typically see at this time of the year. 

This helps us to determine what is known as the "excess mortality", a term used to describe deaths over and above the norm. 

The World Health Organization describes this as the death rate "above what would be expected based on the non-crisis mortality rate in the population". 

It is often used to account for mortality in relation to flu season, or even natural disasters and famine. 

Researchers at Maynooth University and the University of Limerick have helpfully done the work on this by looking at death notices posted to the website RIP.ie. 

They've analysed the numbers of death notices posted from 2010 to present, and found that April 2020 had the highest number of death notices on record overall. 

This map shows the counties marked in red recorded more death notices on this website than any other month over the last decade. 

Those marked in orange recorded the highest number of death notices in the month of April since 2010. 

While the number of death notices posted to RIP.ie in the green counties were below the previous average and therefore showed no signs of excess mortality. 

Researchers say that deaths in Ireland typically peak in winter because of seasonal flu but usually taper off into April. 

The next graph shows this trend on average for the last ten years, and also in the number of death notices for 2019. 

However, when the death notices for April 2020 so far are added in, we can see the number shoots up. 

One of the researchers involved in analysing this data said that on first glance we could compare this spike to the bad flu seasons we experienced a few years ago. 

"January 2017 and 2018 were bad flu seasons, so they have got peaks. If you looked at Ireland on a whole you could say that April 2020 was also some kind of seasonal thing, but just later than usual," explains Dr Pádraig Mac Carron. 

However Dr Mac Carron said that when you break this data down county by county you can see there are five or six that have their highest record of death notices ever. 

"When you compare that to other counties where there has been basically no effect, that are almost the same as the average, you can see that there are certain regions and certain clusters that are being hit a lot harder," he said.

Looking to individual counties, the highest number of death notices overall were recorded for Dublin. 

This is in keeping with the general trend of Dublin having the most confirmed cases of Covid-19. 

Here, there were 1,200 death notices posted to the site in April, a figure that is much higher than the average of 690.

Researchers say this was expected for Dublin.

But the most striking findings from this research relates to the smaller border counties of Monaghan and Cavan, which appear to have been the hardest hit. 

Last month, 80 death notices posted for Monaghan was a marked increase from the April average of 31, while Cavan saw a similar increase. 

There were 125 death notices for Cavan in April, up from an average of just 54. 

"Dublin has a very high population density, so if somebody gets it, it's a lot easier to transmit to a lot of others. Whereas Monaghan has the same population density as Kilkenny. Kilkenny had around the same number of death notices in April 2019 as April 2018, whereas Monaghan was more than twice as high," Dr Mac Carron said. 

The researchers say that while these increases may seem small, they are significant and "unprecedented" in counties like these with low populations. 

Dr Mac Carron said he is confident that the death notices recorded on RIP.ie reflect those compiled by the Central Statistics Office. 

"They correlate very strongly" and it is a "fairly accurate data set," he said. 

Official data released by the Department of Health or Health Protection Surveillance Centre in relation to Covid-19 deaths do not give a county by county analysis, so this research by Maynooth University and the University of Limerick helps to give us more insight into the true impact of the virus.