While Cambridge as a whole became wealthier during the decade between 1979 and 1989, great differences in wealth distribution between the neighborhoods remain, according to recently released Census figures.

In general, the poorer neighborhoods remained poor while the more affluent ones remained affluent. These persisting demographics are "not surprising," says Randall P. Wilson, planning data manager at the Cambridge Community Development Department.

"Any large central city has class and racial divisions and they are geographically and racially specific," says Wilson.

Neighborhood 10, the Brattle Street area, had a per capita income of $41,998 while two of the city's poorest neighborhood's, Area Four and Riverside, each had per capita incomes of about $12,000.

But there were some surprises in the census figures. While the second fastest income growth in the city was posted in the Brattle Street area, the region which grew the fastest was the traditionally working-class neighborhood of East Cambridge.

Overall, while Cambridge's per capita income grew 34.8 percent, income growth in East Cambridge was 84.4 percent.

Hugo Salemme, a trustee of the East Cambridge Stabilization Committee, attributes this growth to a boom in "high tech" industries in East Cambridge.

Salemme says the average income likely grew because "the people who have recently found work in the high tech fields have decided to live in the area" and the children of blue collar families native to the area found jobs in the new firms.

Over the last decade, higher paying industries such as computer software companies have replaced the factories which dominated East Cambridge, says Ilene T. Woodford, the director of neighborhood planning for Cambridge.

"The factories are gone, but Lotus went from two employees to I don't know how many," Woodford says.

Councillor Alice K. Wolf says the census figures illustrate the little-known economic diversity of Cambridge.

"Some people's view of Cambridge is very limited to the universities and so forth and they have a sense of the city as an upper middle-class place. It has great diversity racially and ethnically," says Wolf.

But while the city does have a variety of people from different economic backgrounds, they are divided into different parts of the city.

Wolf says Cambridge is much more racially integrated than economically integrated. "I think certainly there are very significant divisions from an economic point of view," she says.

The census numbers show that the economic differences between neighborhoods have remained more or less consistent during the last decade. And city planners say that the reality of city living ensures that those differences are not likely to change soon.