def print_monthly_returns(fund_ts, years, ostream):
    ostream.write("    ")
    month_names = du.getMonthNames()
    for name in month_names:
        ostream.write("    " + str(name))
    ostream.write("\n")
    i = 0
    mrets = tsu.monthly(fund_ts)
    for year in years:
        ostream.write(str(year))
        months = du.getMonths(fund_ts, year)
        for k in range(1, months[0]):
            ostream.write("       ")
        for month in months:
            ostream.write(" % + 6.2f" % (mrets[i]*100))
            i += 1
        ostream.write("\n")
Implements :func:`autobahn.wamp.interfaces.IObjectSerializer.serialize`
dataset/ETHPy150Open tucker777/QSTK/Bin/report.py/print_monthly_returns--crossover with--dataset/ETHPy150Open crossbario/autobahn-python/autobahn/wamp/serializer.py/UBJSONObjectSerializer.serialize