The secretary shall review the applications from the county governing authority made under RCW 71A.14.030. The secretary may approve an application if it meets the requirements of this chapter and the rules promulgated by the secretary. The secretary shall promulgate rules to assist in determining the amount of the grant. In promulgating the rules, the secretary shall consider the population of the area served, the needs of the area, and the ability of the community to provide funds for the developmental disability program provided in this title.