Measuring the trade share in terms of the quantity of exports (thus avoiding problems due to varying prices over time) and comparing the ratio among the selected commodities, rice had the lowest share of production exported while whole milk powder had the highest. Liapis (2012) also shows that in most cases the export share of production has not changed dramatically over recent decades. Rice, sugar, whole milk powder and soybean oil have experienced rising export shares, shares for maize and butter have declined, and there is no discernible trend in the shares for wheat, soybeans and beef. The conventional view has been that developing countries are net agricultural exporters and developed countries are net agricultural importers.