In the last three decades, the minimum wage in Mexico has actually fallen over time when accounting for inflation. Currently the country's daily minimum wage is only $4.19. A lower house of Congress recently voted in favor of a new policy that could lead to an increase in this minimum wage. Even though this vote was overwhelmingly in favor of an increase, there is an independent commission that must approve it. This commission has been resistant to raise the wage by more than a few pesos per year.
See "Mexico Moves Closer to Possible Minimum Wage Hike", November 13, 2015