Final answer:
While specific data on team serial murders is not provided, examining crime trends suggests that such cases likely have C. stayed the same or changed only slightly.
Step-by-step explanation:
The original question asks about the trend in cases of team serial murders in the United States. While not providing a directly related statistic, examining crime trends can provide some insight.
Based on recent statistics and crime trends, team serial murders are a relatively rare occurrence, and there is no evidence suggesting they have increased sharply or decreased sharply in recent years; hence, the best available answer given the information provided would be that they have stayed the same or changed only slightly.
However, for a precise answer, specific data on team serial murders would be required. In general, for other crime trends and related sociological statistics: life expectancy rates in recent decades have continued to gradually rise, contrasting with the claim of having C. stayed the same since the mid-1960s.
Regarding the unemployment rate, over the long term, it has not consistently trended up or down but has fluctuated due to varying economic conditions.
Lastly, the median age of first marriage has increased for both men and women, reflecting broader social changes.