A recent World Bank research project has generated an annual time series of distortions to agricultural incentives over the past half century for 82 countries, the majority of which are low-and middle-income countries. In this memorandum, the current GTAP version 8 Data Base may be modified to incorporate this dataset, using an Altertax simulation. The files required for this Altertax simulation, including parameter files and shock files are generated by the DAItoGTAP.tab file which will accommodate any level of aggregation of the GTAP database. In this memorandum the data files required to modify the GTAP v8.1 database can be downloaded. Data required to modify the GTAP v9 database will be available at a later date when v9 is released.