Reading 44 Q15

Ok, please don’t laugh, but I have a question regarding part b of Q15 in Reading 44 (return for Mr Smith) - how do they come up with the -9.98% return on the French stocks on page A-23? As I understand, all the cash flows in this problem are supposed to occur at the end of the month, so I thought that the return on those stocks would be computed as - (17,850 - 19,140)/19,140 = -6.74% So, this is return on the Club Med stocks only. How do they get -9.98%? ???