An online stock trading company makes part of their revenue from clients when the clients trade stocks therefore, it is important to the company to have a good idea of how many trades its clients are making in a given year. In a sample of 109 clients of an online stock trading company, the average number of trades per year was 57 with a standard deviation of 18. Find the LOWER bound of the 95% confidence level of the average number of trades the company's clients make. (Please express your answer using 2 decimal places)