Running frequency plotting from matrix

Hi everyone ,I got a homework from Probability course.It says we will roll dice for 200 times and enter the results of that into 200 by 2 matrix (Each result will be a pair, such as (3, 2), which means "3" on the first die, and "2" on the second die).Based on the data we collect , we need to create 6 by 6 matrix that shows running frequency of the pairs ((1,1),(2,2),(3,3)...etc).Running frequency is ; the probability that we want / trials(whole possibility).I already wrote a code about it but i need opinion from everyone how to make it work.

r1=randi(6,200,2) bir=0 i=0 u=0 d=0 bes=0 al=0

a=1 while a>200 if r1(a,:)=(1,1) bir+=1 elseif r1(a,:)=(2,2) i+=1 elseif r1(a,:)=(3,3) u+=1 elseif r1(a,:)=(4,4) d+=1 elseif r1(a,:)=(5,5) bes+=1 elseif r1(a,:)=(6,6) al+=1 end

    freq1=bir/200
    freq2=i/200
    freq3=u/200
    freq4=d/200
    freq5=bes/200
    freq6=al/200

    new_matrix=[freq1,freq2,freq3,freq4,freq5,freq6]

    plot(new_matrix)

By the way instead of rolling 200 dice i created random matrix.