Let’s calculate the percentage of users who has the iPhone app installed.
Since the app was launched on Feb, 1, 2018 let’s consider only users who signed up on this date or later.
As usual, submit the integer part of the answer. For example, if the percentage was 19.87 submit 19 as the answer.
About SQL Habit
Hi, it’s Anatoli, the author of SQL Habit. 
SQL Habit is a course (or, as some of the students say, “business simulator”). It’s based on a story of a fictional startup called Bindle. You’ll play a role of their Data Analyst 
and solve real-life challenges from Business, Marketing, and Product Management.
SQL Habit course is made of bite-sized lessons and exercises (you’re looking at one atm). They always have a real-life setting and detailed explanations. You can immediately apply everything you’ve learned at work. 
