I created some sight tapes using OT2 software. When I set up my Archers Mark Sight tape on I-Phone it ask for 20yd sight in mark and 50yd sight in mark. How do I determine what mark my sight is at ? 20yd mark is at the first large hash mark so what numeral mark would this be ? (0.0?, 1.0?, ). How do I determine this? The sight is a DS Advantage 20/24.