We take advantage of the Brazilian mandatory corporate governance (CG) reporting system to build an overall Brazil Corporate Governance Index (BCGI) and subindices (CGIs), and track changes in firms' scores over the 10-year period from 2010-2019. We show that overall CG level improved significantly between 2010 and 2019, with most of the improvement over the first part of this period. The improvement has two sources: an increase in the proportion of high-standard listings (Novo Mercado and Level 2, NML2) versus low-standard listings (Level 1 and regular, L1R), and within-firm improvement in CG practices. In the first half of the sample period, both NML2 and L1R firms improved CG practices considerably. Overall improvement in the second half of the sample period reflects an increasing proportion of NML2 firms, plus gradual improvement in L1R CG levels; with nearly constant NML2 levels. Improvements were stronger for Board Procedure and Disclosure subindices. Firms in both listings improved their CG. Overall improvement was stronger in NML2 than in L1R, but was concentrated in the period from 2010-2015.