TABLE 1: Desired Output: Ranges of Months with Similar Trends
from_month	to_month	trend
199912	199912	Unknown
200001	200004	Up
200005	200005	Same
200006	200009	Down
200010	200010	Up
200011	200011	Down
200012	200102	Up
200103	200103	Down
200104	200105	Same
200106	200107	Up
200108	200108	Down
200109	200111	Up
200112	200112	Down