Below: Percentage of Blacks in the Mathematical sciences new PhDs prior to 2006.
Data on Minority Doctorates after 2005, is suppressed
statistics on the numbers of Blacks receiving mathematics Ph.D.s before 1993
list of all Black US Ph.D.s in Mathematics by year
YEAR 
TOTAL NEW PHDs in US 
#US citizens 
# Blacks 
# African Americans 
black men : women 
1993 
1,614 
526 
7 (1.3%) 

1994 
1,527 
469 
3 (<1%) 
6 : 5 

1995 
1,226 
567 
6 (1.1%) 
4 : 2 

1996 
1,153 
493 
9 (1.7%) 
6 : 3 

1997 
1,158 
516 
9 (1.5%) 

1998 
1,216 
586 
20 
11 (1.9%) 

1999 
1,113 
438 
19 
12 (2.7%) 
11 : 8 
2000 
1,119 
537 
20 
15 (2.8%) 
14 : 6 
2001 
1008 
494 
28 
14 (2.8) 
9 : 5 
2002 
948 
418 
24 
12 (2.9) 
2 : 1 
2003 
1037 
499 
30 
16 (3.2) 
2 : 1 
2004 

2005 

TOTAL 
10,126 
4230 
62 (1.4%) 
numbers of Blacks receiving
Ph.D.s This data to the right comes from a 1988 handout that is a summary of NRC data for selected fields. It ONLY counts Blacks receiving doctoral degrees who are U.S. and permanent residents. In mathematics, physics (including astronomy) and computer science the numbers are: 

references: The data comes from the NOTICES of the AMS published AMSIMSMAA Annual Surveys (first reports for PhD's in the mathematical sciences at US Universities:
NSF report of undergraduate math majors to PH.D.