What exemptions does a company in a Guatemalan free zone receive, and for how many years?

Under Decree 65-89 (the Free Zones Act), zone administrators enjoy an income tax exemption for fifteen (15) years and users producing industrial goods or services for ten (10) years. In addition, according to advisers' summaries (inbers.com, Vesco): exemption from VAT on transactions inside and between free zones, and exemption from import duties (DAI) and VAT on imports of machinery and inputs. For as long as the income tax exemption lasts, the user also pays no Solidarity Tax (ISO) (Article 4(d), Decree 73-2008).