i have panel time series.
I want to create a variable that is the difference between the last non-missing value and the first non-missing value.so in this case for Austria, the value would be -1 - 0 = "-1".
I want to know the simplest code. I have been creating a variable that is the last value, and another variable that's the first value, and blah blah but i need to do this for so many variables, so i would that'd be a one liner command or something?

thank you!