title: how to change reference point 0 to 100 in MPandroidchart?
body: <p>Now i'm using MP android chart to show the kilowatt per hour data, this requirement need set the benchmark to 100 kwh, if the value is bigger than 100, the line will been draw above the benchmark, if the value is smaller than 100, of course it's below the benchmark. 
  I want to change the benchmark from 0 to 100 on y axis, but i didn't find any useful information from the doc. can someone give any advice on this?</p>