When I run my Fortran code more than once, the value on the file are exactly the same

Question

I am currently working on a Random Walk Fortran program and I was wondering why my the file I create from the program always has the same values after I run it on compilers like Geany and SilverFrost.

Here's the code:

program InfiniteWalk
implicit none
integer :: position(10,1000),n,y,g,z ! The 2 used in the declaration can be changed in order to create n-number of walkers
real::x,onethird,twothird
onethird=1.00/3.00
twothird=2.00/3.00
do n=1,1000
    position(1,n)=n
end do
do z=2,10 !Despite the fact that this do loop is redundant with just 1 "position column", the ending value ought to be modified to the same value as the one made on line 3
    y=1
    do n=1,1000
            call random_number(x)
            if (x .le. onethird) then
                    position(z,n)=y+1
                    y=position(z,n)
            else if ((x .gt. onethird) .and. (x .le. twothird)) then
                    position(z,n)=y-1
            y=position(z,n)
            else    
                    position(z,n)=y+0
            y=position(z,n)
            end if
    end do
end do
open(unit=10,file='InfiniteWalk.txt')
do g=1,1000
    write(10,*) position(1,g),position(2,g),position(3,g),position(4,g)!,position(5,g),position(6,g),position(7,g),position(8,g),position(9,g),position(10,g)!,position(3,g),position(4,g)...position(a,g) [where a is rightmost column #]
end do
end program InfiniteWalk