For decedents in 2017 (with an exemption of $5.49 million), the Tax Policy Center estimates there will be only about 11,000 estate tax returns filed, of which 5,200 will be taxable. Estate tax liability will total $19.7 billion after credits (table 1).
To put the number of estate tax returns filed in perspective, the Population Division of the Census projects that 2.7 million people will die in 2017. Thus, an estate tax return will be filed for only 1 in 243 decedents, and only 1 in 517 will pay any estate tax.
http://www.taxpolicycenter.org/briefing-book/how-many-people-pay-estate-tax