undang undang, uu pasal 21, 2016, 2017, tax amnesty, program, penerimaan, negara, indonesia, wp, npwp, wajib pajak, pajak penghasilan, pendapatan, tarif, nilai, gaji, tahunan, administrasi, pengampunan, pasal 21, pph, cara, penghitungan, perhitungan, tarif, 2018, 2019