How to continue loops with few if statement between them

One thing that I want to do is after first if I want to continue to sum arrival in period between 100 and 200 and so on but I don't know how to do that I want only to sum the values in that period first if is ok but I don't know how to continue:

arrival=xlsread('tripinfo.xlsx','G:G');
depart_time=xlsread('tripinfo.xlsx','B:B');

for i = 1:1:91
    if depart_time(i) < 100
        
        mean_travel1 = sum(arrival(1:i,1));
    elseif 100 < depart_time(i) & depart_time(i)< 200
        mean_travel2 = sum(arrival(i,1));
    elseif 200 < depart_time(i) & depart_time(i) < 300
        mean_travel3 = sum(arrival(i,1));
    elseif 300 < depart_time(i) & depart_time(i) < 400
        mean_travel4 =  sum(arrival(i,1));
    elseif 400 < depart_time(i) & depart_time(i) < 500
        mean_travel5 =  sum(arrival(i,1));
    else 
        mean_travel6 =  sum(arrival(i,1));
        
        
    end
end

Answer 1

[Jan]

This is nicer without a loop:

mean_travel1 = sum(arrival(depart_time < 100,1));
mean_travel2 = sum(arrival(100 < depart_time & depart_time < 200, 1));
... etc.    

By the way, why is depart_time == 100 excluded?

If 100 etc. can be included:

G = discretize(depart_time, [-inf, 100, 200, 300, 400, 500, inf]);
S = splitapply(@sum, arrival, G);

Or with a loop:

mean_travel = zeros(1, 6);  % Better than hiding an index in the name!
for i = 1:1:91
    if depart_time(i) < 100     
        mean_travel(1) = mean_travel(1) + arrival(i,1);
    elseif 100 < depart_time(i) & depart_time(i)< 200
        mean_travel(2) = mean_travel(2) + arrival(i,1);
    elseif 200 < depart_time(i) & depart_time(i) < 300
        mean_travel(3) = mean_travel(3) + arrival(i,1);
    elseif 300 < depart_time(i) & depart_time(i) < 400
        mean_travel(4) = mean_travel(4) + arrival(i,1);
    elseif 400 < depart_time(i) & depart_time(i) < 500
        mean_travel(5) = mean_travel(5) + arrival(i,1);
    else 
        mean_travel(6) = mean_travel(6) + arrival(i,1);
    end
end