What was the total percentage change in exercise price between 2014 and 2016?
{"2 Jul 2012": {"Exercise Date": 2, "Expiry Date": 2, "Exercise Price $": 0.92, "No. of Options at Beg. of Year": 40000, "Options Exercised or Lapsed": -40000, "No. of Options at End of Year": "-"}, "2 Jul 2013": {"Exercise Date": 2.0, "Expiry Date": 30.0, "Exercise Price $": 0.92, "No. of Options at Beg. of Year": 295000.0, "Options Exercised or Lapsed": -220000.0, "No. of Options at End of Year": 75000.0}, "2 Jul 2014": {"Exercise Date": 2.0, "Expiry Date": 2.0, "Exercise Price $": 1.3, "No. of Options at Beg. of Year": 875000.0, "Options Exercised or Lapsed": -405000.0, "No. of Options at End of Year": 470000.0}, "2 Jul 2015": {"Exercise Date": 2, "Expiry Date": 2, "Exercise Price $": 2.67, "No. of Options at Beg. of Year": 1000000, "Options Exercised or Lapsed": "-", "No. of Options at End of Year": 1000000}, "22 Dec 2016": {"Exercise Date": 31, "Expiry Date": 22, "Exercise Price $": 3.59, "No. of Options at Beg. of Year": 1323730, "Options Exercised or Lapsed": "-", "No. of Options at End of Year": 1323730}, "Total": {"Exercise Date": "", "Expiry Date": "", "Exercise Price $": "", "No. of Options at Beg. of Year": 3533730, "Options Exercised or Lapsed": -665000, "No. of Options at End of Year": 2868730}, "Weighted average exercise price": {"Exercise Date": "", "Expiry Date": "", "Exercise Price $": "", "No. of Options at Beg. of Year": "", "Options Exercised or Lapsed": 1.15, "No. of Options at End of Year": 2.82}}
exercise_price_2016 = df["22 Dec 2016"]["Exercise Price $"]
exercise_price_2014 = df["2 Jul 2014"]["Exercise Price $"]
answer = (exercise_price_2016 - exercise_price_2014) / exercise_price_2014 * 100.0