According to a utility company, utility plant expenditures per employee were approximately $50,845, $43,690, $47,098, $56,121, and $49,369 for the years 2005 through 2009. Employees at the end of each year numbered 4738, 4637, 4540, 4397, and 4026, respectively. Using the annual number of employees as weights, what is the weighted mean for annual utility plant investment per employee during this period?