Complex sentence: The NZOC confirmed three gymnasts to compete on 11 May 2016, marking the first time that New Zealand gymnasts have competed at the Olympics since 2000, and New Zealand's largest gymnastics team since 1964.
Split into simpler sentences: The NZOC confirmed three gymnasts to compete on 11 May 2016. It will be first time New Zealand gymnasts have competed at the Olympics since 2000, and New Zealand's largest gymnastics team since 1964.