Complex sentence: The current and main membership of the G8 has remained constant, since Russia joined in at the 1997 G8 Summit at Denver, Colorado; however, the number of aides each leader brings has varied.
Split into simpler sentences: The current and main membership of the G8 has remained constant, since Russia joined in at the 1997 G8 Summit at Denver, Colorado. However, the number of aides each leader brings has varied.