https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/bulletins/2011census/2013-05-16#ethnicity
 
"As previously reported, 80 per cent (45.1 million) of all usual residents in England and Wales in 2011 belonged to the ‘White: British’ ethnic group. This is a seven percentage point decrease since 2001 when 87 per cent (45.5 million) of the usually resident population belonged to the ‘White: British’ group"
 
http://www.ageuk.org.uk/documents/en-gb/for-professionals/equality-and-human-rights/419_0207_ageing_and_ethnicity_in_england_a_demographic_profile_of_bme_older_people_in_england_2007_pro.pdf?dtrk=true
 
Note: the numbers seem off between the two reports, but not by much. See bottom for resolution to this issue
 
control + f and put in "Chart 5: Population pyramids for Ethnic groups in England and Wales" to see the charts I go through
 
Total population: 52,041,916
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Looking at 0-4's
11% of 44,679,361 is 4,914,729.71. This is whites.
18% of 2,248,289 is 404,692.02 Asian
35% of 643,373 is 225,180.55 Mixed
15% of 1,132,508 is 169,876.2 Black
11% of 435,308 is 47,883.88 Chinese
Total: 5,762,362.36
 
Edit: average out the male and female cohorts, dont just add them. Divide by 2.
 
Resolving Number Disparity
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https://en.wikipedia.org/wiki/Demography_of_the_United_Kingdom#Ethnicity
http://archive.is/4AlZk
 
^ only issue is this is the whole UK, whereas the first is England and Wales in 2011, and the second is 2001
 
Perhaps this narrows it down
 
https://en.wikipedia.org/wiki/Demography_of_England#Ethnicity
http://archive.is/5bN72
 
Note: Numbers from age report do match this aside from some confusion among the Chinese classification, add Other Ethnicity to Asian Chinese category and the number checks out (214,619 + 220,681 = 435,300, only 8 off), and the total (neither are of utmost important here, the disparity between totals would actually just make the proportion of white births even higher)
 
Final Remark: The issue with the total populations while every other population number matches up (and considering the wiki article is supposed to be covering England but the numbers of minorities is the same as a study covering England and Wales) suggests there's some confusion among the various regions and in data collection thereabouts.