What was the change in the SaaS and license revenue renewal rate between 2018 and 2019?
{"Other Financial and Operating Data: -- SaaS and license revenue renewal rate(3)": {"2019": 94, "2018": 93, "2017": 93, "2016": 94, "2015": 93}, "Other Financial and Operating Data: -- Adjusted EBITDA(4)": {"2019": 108307, "2018": 93081, "2017": 71628, "2016": 49034, "2015": 34370}}
saas_2019 = df["Other Financial and Operating Data: -- SaaS and license revenue renewal rate(3)"]["2019"]
saas_2018 = df["Other Financial and Operating Data: -- SaaS and license revenue renewal rate(3)"]["2018"]
answer = saas_2019 - saas_2018