BERLIN, April 5 (Xinhua) -- Germany contributes the biggest national share of staff in the European Union's (EU) external border management agency Frontex, German media reported on Thursday.

The reports cited an official document by the Federal Police which showed that Berlin provided a daily average of 114 German customs and security officers to secure the Schengen Frontier in 2017.

Germany consequently accounted for 21.8 percent of the total Frontex contingent last year, followed by Romania, France and the Netherlands.

"The numbers highlight how important the German Frontex mission has become," according to a statement by Dieter Romann, head of the German federal police.

Frontex was founded in 2004 as an EU agency to promote member state cooperation in external border management and is headquartered in Warsaw. The EU has announced plans to widen the scope and increase the staff levels of the organization significantly in response to the refugee crisis.

The Schengen agreement which created a shared external border for its signatories was first established in 1995 and now covers a population of over 400 million inhabitants.

Although principally prohibited within the free-travel area, the refugee crisis witnessed the reintroduction of internal border controls and led to calls for closer and more effective cooperation between member states in external border management.