Read this and answer the question. If the question is unanswerable, say "unanswerable".

Various auto racing organizations hold exhibition events; these events usually award no championship points to participants, but they do offer prize money to participants. The NASCAR Sprint Cup Series holds two exhibition events annually - the Sprint Unlimited, held at Daytona International Speedway at the start of the season, and the NASCAR Sprint All-Star Race, held at Charlotte Motor Speedway midway through the season. Both events carry a hefty purse of over USD $1,000,000. NASCAR has also held exhibition races at Suzuka Circuit and Twin Ring Motegi in Japan and Calder Park Thunderdome in Australia.

How many exhibition events per year does the NASCAR Sprint Cup have?
two