Quite a few. More so in WA than the NT.
You have to remember that even though Australia looks small on a map, the state of WA would cover HALF of the US 48 if laid over the top of it. So it is a bit bigger than Texas !!!

Here is a bit of info I found.

NT Wide Pastoral Survey 2006 - Executive Summary

This survey, conducted in 2004, is the first complete survey of the Northern Territory (NT) pastoral industry.

Three regions were surveyed more than 20 years ago - Alice Springs in 1979, the Barkly in 1980 and Katherine in 1982 - but the Top End pastoral region was not included. This survey reflects the results of interviews with 149 cattle producers across the four regions, accounting for 71% of producers in the NT.

The average size of a cattle station in the NT is 3122km2. On the stations surveyed across the NT there were approximately 1.4 million head. The predominant breed of cattle in the NT is Brahman but British breeds are the most prevalent in the Alice Springs Region, due to a less tropical environment.

The most common ownership structures of stations in the NT are owner/manager (32% of producers), private owned/manager employed (25%) and company/manager (25%). Six per cent of pastoral properties surveyed were Indigenous-owned land.

The majority of properties in the NT have a total herd size between 2000 and 5000 head (20% of properties) and more than 20,000 head (18%). The most common breeder herd size in the NT is that of 2000-5000 head (22%