The number of species below that have two lone pairs of electrons in their central atom is ___ (Round off to the Nearest integer) ${\mathrm{SF}}_4,{\mathrm{BF}}_4^{-},{\mathrm{ClF}}_3,{\mathrm{AsF}}_3,{\mathrm{PCl}}_5,{\mathrm{BrF}}_5,{\mathrm{XeF}}_4,{\mathrm{SF}}_6$