A note about boundaries

	Total Population	Non Hispanic White	Non Hispanic Black	Hispanic	Asian	Other Races
1980	636,212	453,576	145,832	26,111	3,433	7,260
		71.3%	22.9%	4.1%	0.5%	1.1%
1990	628,088	381,714	189,408	39,409	11,429	6,128
		60.8%	30.2%	6.3%	1.8%	1.0%
2000	596,974	270,989	226,742	71,646	19,671	7,926
		45.4%	38.0%	12%	3.3%	1.3%
2010	594,833	220,219	243,059	103,007	22,696	5,852
		37.0%	40.9%	17.3%	3.8%	1.0%
2020	577,222	186,419	231,267	116,306	33,177	10,053
		32.3%	40.1%	20.1%	5.8%	1.7%

1980	1990

2000	2010	2020

Index of Dissimilarity (D)
The dissimilarity index measures whether one particular group is distributed across census tracts in the metropolitan area in the same way as another group. A high value indicates that the two groups tend to live in different tracts. D ranges from 0 to 100. A value of 60 (or above) is considered very high. It means that 60% (or more) of the members of one group would need to move to a different tract in order for the two groups to be equally distributed. Values of 40 or 50 are usually considered a moderate level of segregation, and values of 30 or below are considered to be fairly low. For a more detailed explanation, click here.

Exposure Index
Another measure of residential segregation is a class of exposure indices (p*) that refer to the racial/ethnic composition of the tract where the average member of a given group lives. For example, the average Hispanic in some metropolis might live in a tract that is 40% Hispanic, 40% non-Hispanic white, 15% black, and 5% Asian.(Note that these various indices must add up to 100%.) These are presented below in two categories: exposure of the group to itself (which is called the Index of Isolation) and exposure of the group to other groups). For a more detailed explanation, click here.
Isolation Index
The isolation index is the percentage of same-group population in the census tract where the average member of a racial/ethnic group lives. It has a lower bound of zero (for a very small group that is quite dispersed) to 100 (meaning that group members are entirely isolated from other groups). It should be kept in mind that this index is affected by the size of the group -- it is almost inevitably smaller for smaller groups, and it is likely to rise over time if the group becomes larger. For a more detailed explanation, click here.

Exposure to Other Groups
Indices of exposure to other groups also range from 0 to 100, where a larger value means that the average group member lives in a tract with a higher percentage of persons from the other group. These indices depend on two conditions: the overall size of the other group and each group's settlement pattern. For a more detailed explanation, click here.