Colorado was admitted to the Union as the 38th state in 1876.
Each General Assembly is seated for a two-year period, which corresponds to the two-year terms to which each of the 65 Colorado State Representatives are elected.
When the Colorado General Assembly convenes for its First Regular Session following an even-year election, it begins the first year of a two-year assembly. A year later, that General Assembly will convene for its Second Regular Session of that two-year assembly.
If you subtract 1876 from the current calendar year, the result will be the number of years that Colorado has been a state. Next, divide that number in half to accommodate for the two-year assembly cycle. If the result is an odd number, then round up to the next whole number. That final result will correspond to the number associated with the current General Assembly.