Context : The Dragunov sniper rifle (formal Russian: Снайперская Винтовка системы Драгунова образца 1963 года Snayperskaya Vintovka sistem'y Dragunova obraz'tsa 1963 goda (SVD-63), officially ``Sniper Rifle, System of Dragunov, Model of the Year 1963'') is a semi-automatic sniper/designated marksman rifle chambered in 7.62×54mmR and developed in the Soviet Union. 
Question : In which year was the service entry date for Dragunov sniper rifle?
1963