OKLAHOMA CITY (AP) - Monthly tax collections from oil and natural gas production in Oklahoma slid to the lowest level in 17 years, totaling just $20.8 million in the month of April. State Treasurer Ken Miller released figures on Friday that show overall collections to the state treasury in April were $1.18 billion, the lowest April total in four years. It's about $140 million, or nearly 11 percent less, than collections in April 2015.