查询结果如下：   

年份	分类	数值（十亿美元）
1999-01	Wages and salaries	4,343.30
1999-02	Wages and salaries	4,374.10
1999-03	Wages and salaries	4,379.60
1999-04	Wages and salaries	4,394.50
1999-05	Wages and salaries	4,413.30
1999-06	Wages and salaries	4,421.20
1999-07	Wages and salaries	4,448.40
1999-08	Wages and salaries	4,474.90
1999-09	Wages and salaries	4,495.80
1999-10	Wages and salaries	4,535.10
1999-11	Wages and salaries	4,576.30
1999-12	Wages and salaries	4,639.60
2000-01	Wages and salaries	4,725.30

数据来源：美国经济分析局（Bureau of Economic Analysis）