Combining this with the population numbers from the Home Office and the percentages from that 'bloody old people' table I get these numbers:
18-24: 64% of 5.878.472 = 3.762.222, 2.407.822 voting Remain
25-39: 65% of 12.901.695 = 8.386.101, 3.773.745 voting Remain
40-54: 66% of 13.495.446 = 8.906.994, 3.117.447 voting Remain
55-64: 74% of 7.452.381 = 5.514.761, 1.930.166 voting Remain
65+: 90% of 11.611.167 = 10.450.050, 3.448.516 voting Remain
This adds up to 14.677.696 Remain votes which is 1.5 million
below the actual result.