up to the third decade of life / in late adulthood

[sunyaer]

I found a sentence in a model answer to a test question at http://www.ielts-exam.net/academic_writing_samples_task_1/162/

"The second graph shows that employer support is maximum (approximately 60%) for the under 26yr students. It drops rapidly to 32% up to the third decade of life, and then increases in late adulthood up to about 44%."

Are "up to the third decade of life" and "in late adulthood" correct and natural?

 

[cyberpedant]

They look fine to me.

 

[Linkway]

"Up to the third decade" is inappropriate in this statistical context. It is not clear whether the author means up to the beginning of the decade or the end or during that decade.

It would be far better to use actual age ranges in a consistent (parallel) way.

 

[Rover_KE]

I agree with Linkway.

'Late adulthood' is a particularly nebulous name for an age-group. I consider myself to be in that category and I'm considerably older than 49.