Drink and drug-driving arrests fell just slightly between March and August despite coronavirus restrictions.
Arrests rose by 23% in July, compared to the same month last year, as restaurants and bars reopened following the initial lockdown.
Of the 1,589 arrests made by the PSNI during the period, 310 were for drink or drug-driving.
That figure was down by 53 on the same period last year, when officers made 1,642 arrests, according to a freedom of information request filed by this newspaper.
Over the last four years, police have made 12,593 arrests, with more than a quarter of those coming between midnight and 2.59am. The second highest proportion of arrests happened in the period between 9pm and 11.59pm.
The figures also revealed that almost five times more men were arrested than women over those four years.
Over 45% of people arrested were aged 25 to 39, with the 40 to 54 age group second on 23%.
Forty-five people arrested were under 17, a surprising figure because people are not allowed to drive until they reach that age.
Among pensioners over the age of 70, 194 arrests were made.
The area with the most drink or drug drivers was Belfast, which accounted for 18% of the arrests. The next highest hotspot was the Armagh, Banbridge and Craigavon council area, where around 12% of the total number of arrests was made.
The lowest number of arrests was in the Ards and North Down and Mid and East Antrim areas, which accounted for 6% of detentions.
The most common reason for arrest was driving with excess alcohol, with 10 people detained during the period after returning breathalyser readings over 165 micrograms of alcohol per 100ml of breath. The legal limit is 35. Shockingly, one offender had a reading of 181 micrograms per 100ml - over five times the limit.
The data also provided an insight into the number of arrests made for causing death or grievous bodily injury by driving carelessly with excess alcohol.
Since September 2016, the PSNI has made seven arrests for this reason, with the detentions coming in the Newry, Mourne and Down, Fermanagh and Omagh, and Causeway Coast and Glens council areas.
All of those arrested were men, with one of these being a man over the age of 70 involved in an incident in the Newry, Mourne and Down district.
Joshua Harris, the director of campaigns at the road safety charity Brake, said the figures were worrying.
"Any increase in drink and drug-driving is a significant cause for concern. However, statistics on increases in arrests should be treated with caution unless they are supported by information on enforcement levels," Mr Harris explained.
"Impaired driving is a menace on the UK's roads, responsible for hundreds of deaths and injuries every year. We need tougher laws, including a zero-tolerance drink-drive limit and increased enforcement to help crack down."