Mexico posted a trade surplus of nearly $510 million in April, the National Institute of Statistics and Geography (INEGI) said. The country had posted a trade deficit of $1.22 billion in April 2013, the statistics agency said. The solid performance last month allowed Mexico to reduce its accumulated trade deficit during the first four months of this year to $682.5 million, down 69.6 percent from the $2.24 billion registered in the January-April 2…