Symptom Level     Spatial Coverage     Frequency     Grade     Value   No problems Not applicable Not applicable Not applicable 0 Not applicable Not applicable Not applicable Not applicable -1 Problems observed Any spatial coverage Any frequency / unknown duration Flag F 0.25 Problems observed Any spatial coverage Episodic D Low 0.25 Problems observed Any spatial coverage Episodic DW, W, V Low 0.25 Problems observed Any spatial coverage Episodic M, WM, WS, S, PR Moderate 0.5 Problems observed Any spatial coverage Periodic D Low 0.25 Problems observed Any spatial coverage Periodic DW, W, V Moderate 0.5 Problems observed Any spatial coverage Periodic M, WM, WS, S, PR High 1 Problems observed Any spatial coverage Persistent High 1