Yeah, those are the exact sales in the U.S.
However, you should add more 935,000 copies to the debut album sales since that's what her album sold through the, now extinct, BMG music club. Take a look guys... this was posted in Pulse Music Board's Official Sales Thread =p.
31. BOYZ II MEN - COOLEYHIGHHARMONY (MOTOWN) (1.13 million units)
32. THE NOTORIOUS B.I.G. - LIFE AFTER DEATH (BAD BOY) (1.12 million units)
33. CELINE DION - LET'S TALK ABOUT LOVE (550 MUSIC) (1.11 million units)
34. CELINE DION - ALL THE WAY... A DECADE OF SONG (550 MUSIC) (1.10 million units)
35. JANET JACKSON - JANET JACKSON'S RHYTHM NATION 1814 (A&M) (1.10 million units)
36. ACE OF BASE - THE SIGN (ARISTA) (1.08 million units)
37. BILLY RAY CYRUS - SOME GAVE ALL (MERCURY) (1.08 million units)
38. NATALIE COLE - UNFORGETTABLE (ELEKTRA) (1.03 million units)
39. MARIAH CAREY - #1's (SONY) (1.00 million units)
40. ALICIA KEYS - SONGS IN A MINOR (J) (995,000 units)
41. BACKSTREET BOYS - BLACK & BLUE (JIVE) (992,000 units)
42. RICKY MARTIN - RICKY MARTIN (SONY) (987,000 units)
43. CELINE DION - FALLING INTO YOU (550 MUSIC) (987,000 units)
44. SARAH MCLACHLAN - SURFACING (ARISTA) (985,000 units)
45. PUFF DADDY & THE FAMILY - NO WAY OUT (BAD BOY) (978,000 units)
46. TONI BRAXTON - TONI BRAXTON (LAFACE) (972,000 units)
47. SOUNDTRACK - TITANIC (SONY) (971,000 units)
48. CHRISTINA AGUILERA - CHRISTINA AGUILERA (RCA) (935,000 units)
49. TONI BRAXTON - SECRETS (LAFACE) (927,000 units)
50. MICHAEL JACKSON - THRILLER (EPIC) (923,000 units)
These sales were not counted by Soundscan so they're EXTRA copies ok? So, the final numbers for Christina Aguilera are around 9,145,000 and her total amount goes to 17 million in the U.S.