MATLAB: Separate specific values from matrix

Question

how to separate column 1 values 4541,4546,4546… and their corresponding column 2 values 0,1,2… in a separate matrix

sample matrix

 4541  0
4556  0.025
4558  0.05
4561  0.075
4559  0.1
4559  0.125
4561  0.15
4560  0.175
4561  0.2
4561  0.225
16  0.25
12  0.275
10  0.3
10  0.325
11  0.35
10  0.375
12  0.4
10  0.425
10  0.45
11  0.475
10  0.5
10  0.525
11  0.55
10  0.575
12  0.6
10  0.625
10  0.65
12  0.675
10  0.7
10  0.725
10  0.75
10  0.775
11  0.8
11  0.825
10  0.85
11  0.875
10  0.9
11  0.925
11  0.95
10  0.975
4546  1
4557  1.025
4559  1.05
4561  1.075
4559  1.1
4561  1.125
4561  1.15
4561  1.175
4562  1.2
4561  1.225
17  1.25
12  1.275
10  1.3
11  1.325
11  1.35
10  1.375
12  1.4
10  1.425
10  1.45
12  1.475
10  1.5
11  1.525
10  1.55
10  1.575
11  1.6
10  1.625
10  1.65
11  1.675
10  1.7
11  1.725
10  1.75
10  1.775
12  1.8
10  1.825
11  1.85
10  1.875
10  1.9
12  1.925
10  1.95
10  1.975
4546  2
4557  2.025
4560  2.05
4560  2.075
4559  2.1
4561  2.125
4561  2.15
4561  2.175
4561  2.2
4559  2.225
end

Answer 1

 ind = find(X(:, 1) > 4000);
 Y = X(ind, :);