The bureau said this in the CPI report, which was made available to journalists in Abuja.
It said this was the 16th consecutive month that the index would be recording continuous decline.
The report read in part, “The Consumer Price Index, which measures inflation, increased by 11.61 per cent year-on-year in May 2018.
“This is 0.87 per cent points less than the 13.34 per cent recorded in April, and represents the sixteenth consecutive disinflation since January 2017.”
The NBS report further stated that the urban inflation rate dropped to 12.08 per cent year-on-year in May from 12.89 per cent recorded in April, while the rural inflation rate also dropped to 11.20 per cent in May from 12.13 per cent in April.
On month-on-month basis, the report noted that the urban index rose to 1.1 per cent in May from 0.85 per cent in April, while the rural index also rose to 1.08 per cent in May from the 0.82 per cent recorded in April.
The report stated that in May, inflation was highest in Kebbi (14.65 per cent), Yobe (13.68 per cent) and Jigawa (13.62 per cent).
However, it stated that Kwara, Kogi and Delta recorded the slowest rise in the headline year-on-year inflation at 8.87 per cent, 9.07 per cent and 9.22 per cent, respectively.
On month-on-month basis, it stated that inflation was highest in Adamawa (1.98 per cent), Kwara (1.79 per cent), and Kaduna (1.70 per cent), while Kogi (0.02 per cent), Lagos and Ogun (0.52 per cent each) and Cross River (0.56 per cent) recorded the slowest rise in inflation.
On the food index, the report noted that this rose by 13.45 per cent year-on-year in May, adding that this was caused by an increase in prices of potatoes, yam and other tubers, vegetables, fish, bread and cereals, fruits and meat.
On a month-on-month basis, the food index increased by 1.33 per cent in May, up by 0.42 per cent points from 0.91 per cent recorded in April.