What were the commitments that were less than 1 year as a percentage of total purchase commitments in 2019?
{"Less than 1 year": {"July 27, 2019": 4239, "July 28, 2018": 5407}, "1 to 3 years": {"July 27, 2019": 728, "July 28, 2018": 710}, "3 to 5 years": {"July 27, 2019": "\u2014", "July 28, 2018": 360}, "Total": {"July 27, 2019": 4967, "July 28, 2018": 6477}}
less_than_1_year_July_27_2019 = df["Less than 1 year"]["July 27, 2019"]
total_July_27_2019 = df["Total"]["July 27, 2019"]
answer = less_than_1_year_July_27_2019 / total_July_27_2019 * 100.0