(ShareCast News) - Budget eastern Europe-focused airline Wizz Air reported 23% growth in passenger numbers for December, as it announced new routes to and from Hungary.Passenger numbers last month rose to 1.87m from 1.52m in December 2015, as the load factor - which gauges how full the planes actually are - ticked up to 87.3% from 85.1%.On a rolling 12-month basis, passenger numbers increased 18.8% to 22.78m.In December, the airline won a four-year contract from the Hungarian government to connect Hungary to Macedonia, Albania, Kosovo, Montenegro and Bosnia & Hercegovina starting in April.It also announced that it expanded its network further with 19 new routes to and from Hungary, Bulgaria, Romania, Ukraine, Croatia, and Lithuania, which included the new destinations of Sarajevo, Tirana, Prishtina, and Osijek, while seven new routes started operation.Varna in Bulgaria will become Wizz Air's 27th base with a brand new Airbus A320 aircraft deployed in July and its base expansion will continue with a sixth aircraft to Cluj-Napoca in March and a second aircraft to Kyiv in August.Shares in Wizz Air were up 1.5% to 1,826p at 0800 GMT.