How to make a function that calculates percentage change in a vector

i have a document called gdp.csv which contains a vertical vector of values. How would I make a script that returns the percentage change between every subsequent value?

x=csvread('gdp.csv')

for i=0; i++; i == length(x)-1
  p = (x(i+1)-x(i))/(x(i))
endfor

Answer 1

[KSSV]

Loop:

x=csvread('gdp.csv')
for i=1:length(x)-1
  p = (x(i+1)-x(i))/(x(i))
end

Vector:

p = diff(x)./x(1:end-1) ;