funnel chart conversion

 Hi ,

   I am new to PowerBI and was able to get to a place to show the percentage of drop off in funnel chart.  Help on this would be great.  

I am using the PowerBI chart funnel to show the percent of First. I am sorting the order on the tool tip. 11 is the path sequence is my base. Its not sum of all the step. To calculate funnel conversion rate through steps .

Base for me is path_sequence 11 and step 2 : (path sequence =16)/(path sequence =11) and for step 3:( path sequence =21)/(path sequence =11) 

These are the two questions I have

1. Formatting

I am using powerBI default funnel chart and using data label percentage of first . The first value is always a whole number and I want to convert it to 100%( base)

2. Create a new measure that shows ratio between step2 / base step.

I try to do it manually because of the formatting problem with the funnel .

try for earliest(num_visits) but its throwing error Parameter is not the correct type