Unpacking netcdf files to spreadsheet failure

I am trying to unpack a rather large netcdf file. The dimensions are 12 columns and 2168927 rows. Obviously this is way too large for a single variable or spreadsheet. I don't really need to data, just about 25% of it. I only need the rows with negative latitudes (column 2 of 12) My thoughts were to unpack the entire thing into 2 or 3 spreadsheets and then just extract the data I need manually. I can unpack the data, but I can't seem to parse it into spreadsheets correctly. I can create the two sheets and have data fill in the sheets, but not the right data. Instead of filling in the data from certain xlRange that I create, it creates the first 1000000 rows from the file and all of the columns in both sheets. Both sheets wind up being the same.

Column headers are: 'Date' 'Latitude' 'Longitude' 'Start_Depth' 'Stop_Depth' 'Midpoint_Depth' 'Density' 'Error' 'Elevation' 'SDOS_Flag' 'Method' 'Citation'

Can anyone tell me what I am doing wrong?

Below is my practice code where I am trying to separate out only 20 lines of the spreadsheet into different sheets.

 ncid = netcdf.open('SUMup_datasets_july2018_density.nc','NC_NOWRITE');
%[dimname, dimlen] = netcdf.inqDim(ncid,0)
varname0 = netcdf.inqVar(ncid,0);
varid = netcdf.inqVarID(ncid,varname0);
data0 = netcdf.getVar(ncid,varid);

 varname1 = netcdf.inqVar(ncid,1); 
varid = netcdf.inqVarID(ncid,varname1);
data1 = netcdf.getVar(ncid,varid);
...
varname11 = netcdf.inqVar(ncid,11);
varid = netcdf.inqVarID(ncid,varname11);
data11 = netcdf.getVar(ncid,varid);

 xlRange = 'A1:L20';
xlRange2 = 'A21:L50';
 newData = [data0, data1, data2, data3, data4, data5, data6, data7, data8, data9, data10, data11]; % to append the new column with existing data.
    xlswrite('SUMup_datasets_july2018_density.xlsx', newData,'Sheet1',xlRange);  % to write new data into excel sheet.
  col_header={varname0,varname1,varname2,varname3, varname4, varname5, varname6, varname7, varname8, varname9, varname10, varname11}; %Row cell array (for column labels)
  xlswrite('SUMup_datasets_july2018_density.xlsx',col_header,'Sheet1');     %Write column header 

xlswrite('SUMup_datasets_july2018_density.xlsx', newData,'Sheet2',xlRange2);  % to write new data into excel sheet.
col_header={varname0,varname1,varname2,varname3, varname4, varname5, varname6, varname7, varname8, varname9, varname10, varname11}; %Row cell array (for column labels)
xlswrite('SUMup_datasets_july2018_density.xlsx',col_header,'Sheet2');     %Write column header