In 2022, the population of Index was 156, a 0.00% decrease year-by-year from 2021. Previously, in 2021, Index's population was 156, an increase of 0.65% compared to a population of 155 in 2020.
The median age in Index, WA is 49.5, as per 2021 ACS 5-Year Estimates. Of the total population, 10.90% were under the age of 15, 10.90% aged 15 to 29, 57.05% aged 30 to 64, 18.59% aged 65 to 84, and 2.56% were 85 years of age and older.