The phrase 'concentrate among' is not correct.
The phrase you are looking for is 'concentrate among' or 'focus among.' For example, "I must concentrate among my studies to pass this test."
Since health data show that stressors tend to concentrate among low-SES and people of color (Thoits, 2010), it follows that stressors among these populations may lead to a greater risk of reoffending.
Observed and predicted concentration indices for most of the cost variables are negative meaning that costs concentrate among patients of lower income groups.
Knowledge flows tend to concentrate among participants who are sharing with, and learning from, each other.
Any further inquiry by the IPCC or others should concentrate, among other things, on why these two police responses were so significantly different.
The figure was still high, though, and the anti-Semitic views tended to concentrate among Spaniards with left-of-center political leanings.
Thus, the larger negative value of C, the more costs concentrate among low SES groups.
Obtrusively oaky, overly concentrated wines were rare, and were concentrated among the expensive "luxury" cuvées.
How intelligence is concentrated among the affluent!
The health improvements were, however, more concentrated among the elderly.
Experts said opposition is concentrated among social conservatives.
Child poverty in Britain was once concentrated among the unemployed.
