1906 193,995 1907 187,041 1908 161,584 1909 129,294 1910 109,550 1911 93,821 A reduction of more than one half within five years is matter for public congratulation.[354] Special or commodity rates for the maintenance of equilibrium between competing markets fall naturally into several distinct groups.[355] In the first of these, concerning commodity rates on grain and grain products and cotton, production takes place over a vast extent of territory and the products are marketed in places widely remote from one another. The problem under such circumstances is mainly that of securing equalization through different gateways.[356] In the case of wheat it is a question first of concentration at primary markets, such as St. Paul, Kansas City, or Chicago; and thereafter of carriage by competitive routes whether by the way of the Gulf, by any of the various Atlantic seaports or by the St. Lawrence River. Commodity rates are thus determined in this first class of cases mainly with references to competition of routes. On the other hand, when production is spread over a considerable territory, but when transportation is thereafter effected along converging lines to a fairly localized centre of manufacture, the problem of equalizing conditions, competitively, by the resort to commodity rates, has mainly to do with competitive conditions at the place of production. Rates on wool to the highly localized markets of the world afford illustration of this second type of commodity rate problem.[357] Commodity rates upon fruits and vegetables to common markets from such widely separated sources of supply as Florida and California or the equilibration of conditions of production for coal or lumber from the most widely scattered sources of supply, are perhaps the most difficult of all to settle satisfactorily. * * * * *