Complex sentence: Yilmaz Guney was born in 1931 in the Yenice village of the southern city of Adana, but his identity card was prepared six years later in 1937, that's why his date of birth is commonly known as 1937.
Split into simpler sentences: Yilmaz Guney was born in 1931 in the Yenice village of the southern city of Adana, but his identity card was prepared six years later in 1937. For this reason his date of birth is commonly known as 1937.