get_mutual_fund_returns = function(){
    fn = '../../Data/mutual_funds.txt'
    con = file(fn, open='r')
    data = c()
    while( TRUE ){
        line = readLines(con, n=1)
        line = gsub('\\?\\?', 'NA', line)
        if( length(line)==0 || nchar(line)==0 ){
            break
        }
        T = read.table(text=line)
	number_columns = 1:6
        df = data.frame(T[, number_columns])
        if( length(data)==0 ){
            data = df
        }else{
            data = rbind(data, df)
        }
    }
    close(con)

    data = data.frame(data)
    colnames(data) = c('Name', 'Type', 'Pct_Return_1_Year', 'Pct_Return_5_Year', 'Expense_Ratio', 'Assets')
    rownames(data) = data$Name
    data$Name = NULL

    data$Assets = as.double(data$Assets)
    
    return(data)
}