On Friday, Chair of the Board of Governors of the Federal Reserve System Janet Yellen voiced her concerns over rising economic inequality in the country. According to Yellen, the growing difference between rich and poor is a matter of serious concern for the United States.

In a speech at a conference in Boston on economic opportunity, Yellen said that trends in the recent decades showed that income and opportunity gap in the country is approaching its widest point. According to Yellen, the Great Recession had narrowed the gap between rich and everyone, but after that it has accelerated. The robust market has helped middle-class America in employment and wages, she added.

While speaking in the conference, Yellen talked about the data that showed the top 5% American households' average income was rising by 38% between 1989 and 2013. The remaining 95% American households grew less than 10% during the same time, she said.

During her speech, Yellen also talked about the widening gap in overall wealth. According to the chair of Federal Reserve System, 50% families in the United States, about 60 million households, had net worth of about $11,000 last year. While adjusting for inflation, Yellen said that the figure was about 50% lower than what it was in 1989. 17 percent of the households even have reported zero or negative net-worth.

Yellen compared the figures with a data report, which showed that the actual net worth of families in the top 5% jumped to $6.8 million in 2013 from $3.6 million in 1989.

Yellen, who has previously served as Vice Chair from 2010 to 2014, did not directly address the economic outlook or monetary policy of the United States in her speech. She kept her focus on childhood education, business ownership, inheritances and affordable higher education.