What is the population of the country to which  the Croatian road A9 leads ?
A9 (Croatia) The A9 motorway (Croatian: "Autocesta A9" ) is a north–south motorway in Croatia, with a length of 78.3 km . Beginning in Pula, the largest city on the Istrian peninsula, it runs north to the Croatian motorway and expressway network at the Kanfanar interchange. Here it meets the A8 motorway, forming the Istrian Y road system. The A9 continues north from here to the Kaštel and Plovanija border crossings into Slovenia. The motorway represents a significant north–south transportation corridor in Croatia and is a part of the European route E751. The motorway's national significance is reflected in the positive economic impact on the cities and towns it connects, as well as its importance to tourism in Croatia. Importance of the motorway for tourism is particularly high during summer tourist seasons, when traffic volume increases by more than 80%.
D21 road (Croatia) D21 is a 80.1 km , north–south state road in Istria County, Croatia. A short section of D21 is a part of the European route E751. The northern terminus of the route is located at the Croatia–Slovenia border at the Dragonja River. There it connects to Koper, Slovenia, and Trieste, Italy, via the Slovene route G11 further north. D21 route is generally parallel to A9 motorway. The two form several junctions, either directly or via short connectors, at Buje, Bale and Vodnjan – towns served directly by D21. The southern terminus of the route is found in the city of Pula, at the southern tip of the Istrian Peninsula.