As the pressure increases, the density increases (see image attached)
At the range of pressure of 0.2 to 1.4 millions atmospheres, the density will be 3.4-5.6 g/cm³
At the range of pressure of 1.4 to 3.1 millions atmospheres, the density will be 9.9-12.2 g/cm³
At the range of pressure 3.1 to 3.6 millions atmospheres, the density will be 12.8-13.1 g/cm³
So, the answer is at the range 1.4 to 3.1 millions atmospheres
