Income inequality has spiked over the course of nearly three decades, with new figures showing the top 10 per cent of US families hold 76 per cent of total wealth in this country.

The bottom 50 per cent of families made up just 1 per cent of the country's total wealth in 2013, according to figures released by the Congressional Budget Office on Thursday.

Among those at or below the 25th percentile, average debt has grown from $1,000 in 1989 to $13,000 by 2013.

The top 10 percent of families, possessing an average of $4million each, held 76 per cent of total wealth, while the bottom 50 per cent cumulatively held just one per cent

While wealth among families at the 90th percentile grew by 54 per cent between 1989 and 2013, numbers fell among the second to lowest quarter

In 2013, the combined wealth of families in the US was a whopping $67 trillion, with the median family holding about $81,000.

But the top 10 percent of families, possessing an average of $4million each, held 76 per cent of total wealth.

Everyone else in the top 50 per cent accounted for another 23 per cent, with an average of $316,000 for each family in this bracket.

This left just one percent of the wealth pie to everyone in the bottom 50 per cent.

While wealth among families at the 90th percentile grew by 54 per cent between 1989 and 2013, numbers fell among the second to lowest quarter.

Among families in the 26th to 50th percentiles, average wealth plummeted from about $64,338 in 2007 to just $36,000 in 2013 clocking in below wealth in 1989, which stood at about $38,297.

At the very bottom quarter, families had an average of $13,000 in debt in 2013, a significant increase from just $1,000 in 1989.

Among families in the 26th to 50th percentiles, average wealth plummeted from about $64,338 in 2007 to just $36,000 in 2013 clocking in below figures in 1989, which stood at about $38,297

At the very bottom quarter, families had an average of $13,000 in debt in 2013, a significant increase from just $1,000 in 1989

According to the CBO, after the recession, the drop in average wealth among the bottom quarter could be explained by the drop in home equity, as well as the rise in non-mortgage debt

According to the CBO, after the recession, the drop in average wealth among the bottom quarter could be explained by the drop in home equity, as well as the rise in non-mortgage debt, which consists of credit card balances, consumer loans or student loans.

While families run by an adult with a graduate degree managed to weather the recession, median wealth is on a slight uptick for those with a bachelor's degree after a significant drop from 2007 to 2010.

From a longer-term perspective, median wealth has increased substantially among families headed by someone with a bachelor's degree between 1989 and 2007.

The CBO calculated 'marketable wealth', like real estate, stocks, money in bank accounts or equity in businesses by subtracting non-mortgage debt from the assets.