Arduino and Matlab Serial communication is slow.

I am sending 10k data from MKR Zero Arduino to MATLAB with serial communcation. The data is finished sending from the Arduino in 3 seconds but the Matlab connot catch up the speed and take more than 5 minutes. Besides, I am plotting the data in GUI and my following codes are below:

I am using fscanf to get the data and define the array before the loop

function testingbtn_Callback(hObject, eventdata, handles)
Y = zeros(10000,1); T = zeros(10000,1);
global X; 
%Check COM9's availabillity 
ports = serialportlist;

%Check if the Arduino is connected 
if ( (logical(nnz(ports == "COM9"))) && (~isempty(ports)) )
    if (string(X.status) == "open")
        %Send '0' as string to Arduino
        fprintf(X,'3');
        
        %Print log
        prevlog = get(handles.logtext, 'string');
        if (size(prevlog,1)==10) 
            prevlog(1,:)=[];
        end
        log = [prevlog; ": MODE = TESTING!"];
        set(handles.logtext,'string', log);
        
        %Change button colour
        set(handles.testingbtn,'BackgroundColor','green','enable','on');
        index = 1;

        while get( hObject, 'value')
            output = fscanf(X,'%f');
            T(index) = index;
            Y(index) = output;
            plot(handles.Graph1, T, Y);
            index = index + 1;
            drawnow
        end
        
    elseif (string(X.status) == "closed")
        %Print log
        prevlog = get(handles.logtext, 'string');
        if (size(prevlog,1)==10) 
            prevlog(1,:)=[];
        end
        log = [prevlog;  ": TURN ON STATUS, PRESS CONNECT BUTTON"];
        set(handles.logtext,'string', log);
    else
        fprintf(X.status);
    end
else
    %If arduino is disconnected 
    prevlog = get(handles.logtext, 'string');
    if (size(prevlog,1)==10) 
        prevlog(1,:)=[];
    end
    log = [prevlog;  ": FAILED! ARDUINO DC!"];
    set(handles.logtext,'string', log);
end

By the way, the type of data I am sending is numerical as below:

676

155

-327

-826

-871

-811

-718

-502

8

319

304

276

7

-170

-376

-475

-584

-577

-327

-240

-62