Arithmetic overflow error converting numeric to data type numeric - SQL 2008

Msg 8115, Level 16, State 8, Line 178

Arithmetic overflow error converting numeric to data type numeric.

The statement has been terminated.



I have a report that calls the below mentioned SQL Function cusPovLevel_Revision. Above is the error I got back when running a set date range. After some investigating, I found the client to have a few patients with an annual income of 999999996.00. Obviously a data entry error. I have tried mofifying the function to account for this large number and cant seem to make it work right. Any help is appreciated.

USE [demo];
GO
/********************************************************************************************************
***** Object:  UserDefinedFunction [dbo].[cusPovLevel_Revision]    Script Date: 07/30/2013 11:05:18 *****
********************************************************************************************************/
SET ANSI_NULLS ON;
GO
SET QUOTED_IDENTIFIER ON;
GO
ALTER FUNCTION dbo.cusPovLevel_Revision
    (
      @liIncome INT ,
      @liFamilySize TINYINT ,
      @lcSFEffectiveDte CHAR(8)
    )
RETURNS INT
AS 
    BEGIN
        DECLARE
            @liBaseIncome NUMERIC(12 , 2) ,
            @lcPayPovCode CHAR(3) ,
            @liPayPovID INT ,
            @lcFamilySize CHAR(3) ,
            @liPctPov DECIMAL(8 , 3) ,
            @lcCode VARCHAR(200) ,
            @liMedListsId INT ,
            @liRetVal INT ,
            @lnCsrBaseIncome NUMERIC(12 , 2) ,
            @lcCsrEffDte CHAR(8) ,
            @lnRetValBaseIncome NUMERIC(12 , 2) ,
            @lnIncome NUMERIC(12 , 2) ,
            @lnCode NUMERIC(12 , 2) ,
            @liSFScheduleID INT; 
        IF @liFamilySize > 15 
            BEGIN
                SET @lcFamilySize = '15';
            END
        ELSE 
            BEGIN
                SET @lcFamilySize = CAST(@liFamilySize AS VARCHAR);
            END;
        DECLARE @csrBaseIncome CURSOR;
        SET @csrBaseIncome = CURSOR
        FOR SELECT BaseIncome = CAST( description AS numeric( 12 , 2 )) , 
                   EffectiveDteString = LEFT( LTRIM( FunctionName ) , 8 )
              FROM cusCRIMedLists
              WHERE code = @lcFamilySize
                AND tablename =  'baseincome'
                AND FunctionName IS NOT NULL
              ORDER BY EffectiveDteString DESC;
        SET @lnRetValBaseIncome = -1.00;
        OPEN @csrBaseIncome;
        FETCH NEXT FROM @csrBaseIncome INTO @lnCsrBaseIncome , @lcCsrEffDte;
        WHILE @@FETCH_STATUS = 0 
            BEGIN
                IF @lcSFEffectiveDte >= @lcCsrEffDte 
                    BEGIN
                        SET @lnRetValBaseIncome = @lnCsrBaseIncome;
                        BREAK;
                    END;
                FETCH NEXT FROM @csrBaseIncome INTO @lnCsrBaseIncome , @lcCsrEffDte;
            END;
        CLOSE @csrBaseIncome;
        DEALLOCATE @csrBaseIncome;
        IF @lnRetValBaseIncome = -1.00 
            BEGIN
                RETURN 0;
            END;
        ELSE 
            BEGIN
                SET @liBaseIncome = @lnRetValBaseIncome;
                SET @lnIncome = CAST(@liIncome AS NUMERIC(12 , 2));
                SET @liPctPov = @liIncome / @liBaseIncome * 100;
                DECLARE @CrsrVar CURSOR; 
                SET @CrsrVar = CURSOR
                FOR SELECT Code , 
                           MedListsId
                      FROM cusCRIMedLists
                      WHERE TableName = 'SlidingFeeScheduleDtl'
                        AND JoinId IN( 
                                       SELECT MedListsId
                                         FROM MedLists
                                         WHERE tablename = 'SlidingFeeSchedule' AND Code = 'S'
                                     )
                      ORDER BY CAST( Code AS INT );
                OPEN @CrsrVar;
                FETCH NEXT FROM @CrsrVar INTO @lcCode , @liMedListsId;
                WHILE @@FETCH_STATUS = 0 
                    BEGIN
                        SET @liRetVal = @liMedListsId;
                        SET @lnCode = CAST(@lcCode AS NUMERIC(12 , 2));
                        IF @liPctPov <= @lnCode 
                            BEGIN
                                BREAK
                            END;
                        FETCH NEXT FROM @CrsrVar INTO @lcCode , @liMedListsId;
                    END;
                CLOSE @CrsrVar;
                DEALLOCATE @CrsrVar;
                DECLARE @liPctPovInt INT;
                SET @liPctPovInt = ROUND(@liPctPov , 0);
                RETURN ROUND( @liPctPovInt , 0);
            END;
        RETURN 0;
    END;
GO