71.   The largest proportion of teen births occurs among Hispanics, she said.

72.   The most significant change in family structure, the studies suggest, has occurred among low-income blacks.

73.   The most significant change has occurred among blacks.

74.   The same trend occurs among Native Americans and Hispanics.

75.   The smallest decline in nighttime working has occurred among the worst-paid workers, and blacks have found it harder than whites or immigrants to escape such work.

76.   The three deaths that occurred among mothers who took AZT were due to AIDS and not the drug, the researchers said.

77.   The U.N. said it saw early warning signs that epidemics of similar magnitude could occur among Asian countries, where HIV has been a relative latecomer.

78.   These explosions probably occur among young, massive stars, so gamma-ray bursts may contain a hidden message about how galaxies evolve.

79.   This argument can also offer a fairly benign explanation for the recent decline in happiness, precisely because it has occurred among women.

80.   This erosion was pronounced among janitors but did not occur among clerical workers , for example, who did not face competition from outside contractors.