<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 11
<NAME> SR FLOATING RATE
<MULTIPLIER> 1
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> JUL-31-2000
<PERIOD-START> AUG-01-1999
<PERIOD-END> JUL-31-2000
<INVESTMENTS-AT-COST> 1,534,728,685
<INVESTMENTS-AT-VALUE> 1,449,632,114
<RECEIVABLES> 13,710,067
<ASSETS-OTHER> 516,136
<OTHER-ITEMS-ASSETS> 33,624
<TOTAL-ASSETS> 1,463,891,941
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 6,283,333
<TOTAL-LIABILITIES> 6,283,333
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,536,238,284
<SHARES-COMMON-STOCK> 152,178,276
<SHARES-COMMON-PRIOR> 145,951,374
<ACCUMULATED-NII-CURRENT> 3,604,417
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 2,862,478
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (85,096,571)
<NET-ASSETS> 1,457,608,608
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 140,920,030
<OTHER-INCOME> 2,110,975
<EXPENSES-NET> (26,059,391)
<NET-INVESTMENT-INCOME> 116,971,614
<REALIZED-GAINS-CURRENT> 3,089,393
<APPREC-INCREASE-CURRENT> (84,184,679)
<NET-CHANGE-FROM-OPS> 35,876,328
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (116,807,793)
<DISTRIBUTIONS-OF-GAINS> (1,076,619)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 57,196,384
<NUMBER-OF-SHARES-REDEEMED> (59,220,564)
<SHARES-REINVESTED> 8,251,082
<NET-CHANGE-IN-ASSETS> (14,344,029)
<ACCUMULATED-NII-PRIOR> 3,303,975
<ACCUMULATED-GAINS-PRIOR> 849,704
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 15,073,901
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 26,059,391
<AVERAGE-NET-ASSETS> 1,587,053,340
<PER-SHARE-NAV-BEGIN> 10.090
<PER-SHARE-NII> 0.720
<PER-SHARE-GAIN-APPREC> (0.500)
<PER-SHARE-DIVIDEND> (0.720)
<PER-SHARE-DISTRIBUTIONS> (0.010)
<RETURNS-OF-CAPITAL> 0.000
<PER-SHARE-NAV-END> 9.580
<EXPENSE-RATIO> 1.64
</TABLE>
