WASHINGTON: Millennials are now the single biggest age group in the US and are far more diverse than any other generation according to new data from the US Census Bureau.

It estimated that, as of 1 July 2014, the number of Americans born between 1982 and 2000 stood at 83.1m – more than a quarter of the total population – and 44.2% of these came from a minority race or ethnic group.

The shifts under way were further emphasised in the finding that the under-five age group was now "majority-minority", as 50.2% were part of a minority race or ethnic group.

That same "majority-minority" tag could also be applied to five states: Hawaii (77.0%), the District of Columbia (64.2%), California (61.5%), New Mexico (61.1%) and Texas (56.5%).

Overall the major groups within this classification are growing. The Hispanic population was the largest, totalling 55.4m in July 2014, up 2.1% on a year earlier.

The African-American population was 45.7m, a 1.3% increase, and Asian-Americans numbered 20.3m, a 3.2% increase.

The numbers of the smaller groups have also swelled: the American Indian and Alaska Native population was up 1.4% to 6.5m while that of Native Hawaiians and Other Pacific Islanders rose 2.3% to 1.5m.

The slowest-growing group was the nation's non-Hispanic, white population which edged up 0.5% to 197.9m.

Unsurprisingly, the least diverse age group is the oldest. There are now some 46.2m over-65s – a group that also includes the oldest four years of the Baby Boomer generation – of whom only 21.7% are from a minority.

The oldest states were Florida and Maine, the youngest Alaska and Utah. And in contrast to most states, five experienced a decline in median age between 1 July 2013 and 1 July 2014: North Dakota, Hawaii, Montana, Wyoming and Iowa.

Data sourced from PR Newswire; additional content by Warc staff