What was to become the Israeli diamond industry began in 1937, eleven years before the State of Israel was established, when the first diamond polishing plant was opened in Petah Tikva by refugee experts from the Netherlands.[5] In 1938 the 15% import duty on imported rough stones was removed. By 1944 the industry employed 3,300 workers in 33 factories, with £P 1,320,000 capital investment, entirely Jewish. The value of exports was over £P 3,200,000 mainly to the United States, Canada, and India; it was the largest value of any single commodity exported from Mandatory Palestine that year.[6]