The Basic Education Act of 1977 established the current formula for general apportionment to school districts, with the objective of equalizing educational opportunities among districts by providing all districts with the resources for a basic education program. This is accomplished by an equitable distribution of funds for teaching, administration, support, and maintenance staff and other non salary items such as supplies, instructional materials, technology, utilities, insurance, security, and maintenance. The distribution formula is a prototypical school model. It allocates funds primarily on the basis of class size, building staffing levels, and administrative, instructional, and non-instructional staff costs, depending on the number of students and district salary levels, along with an allowance for non salary costs. Additional calculations include allowances for the staffing needs of schools with small enrollments. The general apportionment formula also provides funding for secondary vocational programs and skills centers. These, in combination with school districts' basic education programs, are intended to increase the employability of youth and to facilitate entry into skilled trades and occupations. The general apportionment formula is a distribution model and aside from maintaining minimum staff ratios, districts may use the funding for any educational purpose.