title: Which is the best way to find percentage change of list of values in a timeserie
body: <p>I have a series of timeseries data </p>
  
  <pre><code>delay(10)
  espData=[value,100,1513298528793]
  delay(10)
  espData=[value,110,1513298528803]
  delay(10)
  espData=[value,120,1513298528813]
  delay(10)
  espData=[value,130,1513298528823]
  delay(10)
  espData=[value,140,1513298528833]
  </code></pre>
  
  <p>I am wondering weather slope calculation in linear regression will help me find the percentage change (negative/positive)</p>