The number of appeals filed with the Board of Revision of Taxes (BRT) is the highest number since 2014, when the city implemented a new system of valuing properties at 100 percent of market value. The number of appeals has grown since the Oct. 1 deadline to file them because the city had not completed all of the 20,000 informal appeals, known as first-level reviews, by October. After first-level reviews are complete, taxpayers can choose to file a formal appeal.