问在Python中发出跟踪错误

EN

department = raw_input
salesQuarterOneThisYear = input
salesQuarterTwoThisYear = input
salesQuarterThreeThisYear = input
salesQuarterFourThisYear = input
salesQuarterOneLastYear = input
salesQuarterTwoLastYear = input
salesQuarterThreeLastYear = input
salesQuarterFourLastYear = input
QUIT = 'ZZZZ'
print 'Enter department name or', QUIT,'to quit:'
raw_input('')

while department != QUIT:
    print 'Enter sales for first quarter this year:'
    salesQuarter1ThisYear = input('')
    print 'Enter sales for second quarter this year:'
    salesQuarter2ThisYear = input('')
    print 'Enter sales for third quarter this year:'
    salesQuarter3ThisYear = input('')
    print 'Enter sales for fourth quarter this year:'
    salesQuarter4ThisYear = input('')
    print 'Enter sales for first quarter last year:'
    salesQuarter1LastYear = input('')
    print 'Enter sales for second quarter last year'
    salesQuarter2LastYear = input('')
    print 'Enter sales for third quarter last year:'
    salesQuarter3LastYear = input('')
    print 'Enter sales for fourth quarter last year:'
    salesQuarter4LastYear = input
    total_this_year = salesQuarterOneThisYear + salesQuarterTwoThisYear + salesQuarterThreeThisYear + salesQuarterFourThisYear
    total_last_year = salesQuarterOneLastYear + salesQuarterTwoLastYear + salesQuarterThreeLastYear + salesQuarterFourLastYear
    print 'Total this year = ',total_this_year
    print 'Total last year = ',total_last_year
    if total_this_year is total_last_year:
        print 'Status = Same'
    if total_this_year > total_last_year:
        print 'Status = Higher'
    if total_this_year < total_last_year:
        print 'Status = Lower'

    print

    print 'Department: ',department
    if total_this_year is total_last_year:
        print 'Status = Same'
    if total_this_year > total_last_year:
        print 'Status = Higher'
    if total_this_year < total_last_year:
        print 'Status = Lower'

    print 'Enter department name or', QUIT,'to quit:'
    raw_input('')

  File ..., line 31, in <module>
    total_this_year = salesQuarterOneThisYear + salesQuarterTwoThisYear + salesQuarterThreeThisYear + salesQuarterFourThisYear
TypeError: unsupported operand type(s) for +: 'builtin_function_or_method' and 'builtin_function_or_method'