求翻译：在目前的通用航空的市场结构中，上述内容仍占相当比例，但份额已在逐步下降；自发的市场需求在逐年增长，其作业价格完全按照市场供需关系来确定，主要的经营项目有石油服务、公务飞行、医疗救护、培训飞行等等。是什么意思？

In the current market structure in general aviation, still a considerable proportion of the above, but the share has gradually declined; spontaneous demand increased year by year, the price of its operations in full accordance with market supply and demand to determine the major oil services project

In the current general aviation in the structure of the market, the above content is still a substantial proportion, but has been a gradual decline in share; spontaneous market demand has been increasing in price, its operation is completely in line with the market demand and supply, the main operat

In the present general utility aviation market mechanism, the above content still accounted for the perspective, but the share was dropping gradually; The spontaneous market demands are growing year by year, its work price defers to the market supply and demand relations to determine completely, the

In the present market structure in general aviation, this is still a substantial proportion, but share has gradually decreased spontaneous market demand increased, according to supply and demand determine the price in full conformity with its job market, major projects petroleum services, official f

In the structure of market of present common aviation, the above-mentioned content still takes the about equal proportion, but the share has been already dropping progressively; The spontaneous market demand increases year by year, its price of homework totally fixes according to the relation of sup