Upon written request from the public, the bank shall make available the names of executive officers and principal shareholders to whom, or to whose related interests, any correspondent bank had outstanding at any time during the previous year an extension of credit that, when aggregated with all other extensions of credit at such time from all correspondent banks to that person and the related interests of that person, equals or exceeds 5 percent of unimpaired capital and unimpaired surplus or $500,000, whichever is less. Records of such requests must be maintained for two years.