 The city of Zagreb alone contributes 30.9 percent of Croatia's GDP, followed by Zagreb and Varaždin counties, contributing 5.5 percent and 3.6 percent of the nation's GDP respectively.taken on its own, the area contributes 54.5 percent of Croatia's GDP and has an average GDP per capita of 12,446 euros—16.7 percent above the national average.By 2011, the national GDP share increased further for the city of Zagreb and Zagreb County, reaching 31.4 percent and 5.7 percent respectively.