Every such insurer, through its president and secretary, shall keep or cause to be kept accurate records and accounts of its transactions. The books, files and records of the insurer shall be located at its principal place of business in this State or at such place in this State as may be expressly authorized by the insurer's board of directors with notice thereof in writing to the Commissioner. The books, files and records of the insurer shall be available for inspection by the insurer's directors and officers and by the Commissioner at all reasonable times.