About 10% as of 2015[1]:

> Unlike child support, which is common when divorcing couple has kids, alimony awards have always been very rare, going from about 25 percent of cases in the 1960s to about 10 percent today, said Judith McMullen, a professor of law at Marquette University. In one study of Wisconsin cases, she found it was only 8.6 percent.

[1] https://www.reuters.com/article/idUSKCN0T61O8/

My guess would be that this would depend on income bracket.

My worry if divorced would be splitting up my retirement savings. Alimony would probably be comparatively cheap.

Still, most people who get divorced probably have nothing to divide and no income to divert to the poorer spouse.

If you look at mid-to-high-income homes, I bet alimony goes up.

Yes, in community property states, money and property acquired during the term of a marriage get split--but this is not restricted to money and property acquired by the husband.