Before revision:  I estimate that, among adults aged 45+, about 28,000 excess deaths were registered in the 4 weeks comprising 21 March through 17 April (612 \pm 416 from 21-27 March, 5675 \pm 439 from 28 March through 3 April,  9183 \pm 468 from 4-10 April, and 12,712 \pm 589 from 11-17 April\pm  ).
After revision:  I estimate that, among adults aged 45+, about 28,000 excess deaths were registered in the 4 weeks comprising 21 March through 17 April (612 \pm 416 from 21-27 March, 5675 \pm 439 from 28 March through 3 April, then 9183 \pm 468 from 4-10 April, and 12,712 \pm 589 from 11-17 April\pm ).