YEREVAN, Sept 4 (Reuters) - Armenia's gross domestic product grew by 5.5 percent in the second quarter of this year, official data showed on Monday, better than the same period in 2016 when it expanded by just 1.5 percent.

The Caucasus nation's economic growth slowed to 0.2 percent last year, falling well short of the government's original target of 2.2 percent.

This year's figures are better so far. GDP growth hit 6.5 percent in the first quarter of 2017, outstripping a 4.4 percent rise in the same period a year earlier.

The country of 3.2 million depends heavily on aid and investment from former imperial master Russia, whose economic downturn has hit Armenian exports and remittances from Armenians working there.

The government expects the country's economy to grow by 3.2 percent this year, helped by lower borrowing costs and increased exports to Russia. The central bank said last month it had raised its forecast for GDP growth to 3.9-4.8 percent this year, up from an earlier estimate of 3.3-4.8 percent. (Reporting by Hasmik Mkrtchyan; Writing by Margarita Antidze; Editing by Andrew Osborn)