大家好，小弟备考Base 考试，第29题请求解惑。

data Work.INFO;
       infile 'DATAFILE.TXT';
       input @1 Company $20. @25 State $2. @;
       if State=' ' then input @30 Year;
       else input @30 City Year;
       input NumEmployees;
run;
How many raw data records are read during each iteration of the DATA step?
Answer: 2
请问有大侠能解惑吗? 真没看明白70题那个解释。