Complex sentence: By the end of 1999, "Boys & Girls" had sold over 1,037,950 units in Japan, thus being ranked at number 11 on Oricon's Annual 1999 chart.
Split into simpler sentences: By the end of 1999, it had sold over 1,037,950 units in Japan. It was additionally ranked at number 11 on Oricon's Annual 1999 chart.