Minimum density requirement is .05 gpm.
That said designing to the sprinkler head data sheets you'll automatically meet or exceed that.
For example Vikings Freedom Residential Sprinkler VK436 has a minimum flow requirement of 17.0 gpm for an 18'x18' area of coverage. 17.0^2 = 324 sq ft. 324*.05=16.2 gpm. 17.0 gpm meets or exceeds the .05 minimum requirement. Same head for 20'x20' requires 20.0 gpm which is .05 gpm.
Where using residential sprinklers outside the dwellign units, a corridor for example, you must meet the density for light hazard of .10 gpm but only four sprinklers need be in the calculations as long as they are listed residential sprinklers.