Prices of housing and utilities made the largest contribution to the increase in the CPI rising 2.5 percent year-on-year, the same rate as in April.
Also, as the Pentecost holiday fell in May (it was in June in 2014) there were more days off increasing demand for leisure travel which resulted in higher prices of airfares (17 percent from -10.7 percent) and hotels, cafes and restaurants (2.9 percent in May from 1.8 percent in April).
Additional upward pressure came from miscellaneous goods and services (2.2 percent from 2.1 percent), food (0.3 percent from -0.2 percent) and recreation and culture (1.2 percent from -0.6 percent).
In contrast, downward pressure came from clothing and footwear (-2.6 percent) and household appliances (-1.1 percent).
Core inflation increased to 1.8 percent from 1.1 percent.
On a monthly basis, consumer prices increased 0.6 percent, slowing from a 1.1 percent rise in March.
The harmonized index rose 0.7 percent on the year and 0.2 percent from the previous month (0.0 percent and 0.8 percent respectively in April).