Hello, everyone.

I want to describe the situation that the number of men with depression and the number of women with depression are both on the increase, but don't know the correct expression.

Which one of the following is correct?

(1.a) The number of men and women with depression is on the increase.
(1.b) The number of men and women with depression are on the increase.
(2.a) The numbers of men and women with depression is on the increase.
(2.b) The numbers of men and women with depression are on the increase.

Any suggestions and advices would be geatly appreciated. Thank you.