Vegetables maturity time, production in per sq.ft

I am looking for a freelancer to help me understand the maturity time and production of various vegetables per square foot. Specifically, I am interested in tomatoes, carrots and spinach. I have specific timelines in mind and need to know the potential minimum yield for each vegetable. The successful freelancer will answer questions related to this project and provide insight on the maturity timeframe and potential yield in a timely manner. I am looking for someone who has knowledge of the industry and can clearly explain their findings in a concise manner. Successful completion of this project will include gathering and analyzing market data and trends, as well as providing a comprehensive report summarizing the findings.