Analisis tarif rasional berdasarkan kemampuan dan kemauan membayar masyarakat di Puskesmas Lubuk Along, Kabupaten Padang Pariaman, Propinsi Sumatera Barat, tahun 2000 = Analysis of Rational Rate Based on Ability and Willingness to Pay in Lubuk Alung Public Health Center, Padang Pariaman District, West Sumatera Province Year 2000