The average cost to rent a self-storage unit is going up. In an analysis of the top 200 U.S. markets by number of reservations, SpareFoot pricing data indicates the average monthly cost to rent a self-storage unit last year was $91.14. That’s a 4.5 percent increase compared to the 2016 average. On a per-square-foot basis, the national average was $1.01, compared to $0.97 in 2016, according to information recently released by the online marketplace

Among the five most common unit types, rental prices increased year over year:

San Francisco operators posted the most expensive average rates at $168 per month, followed by Gardena, Calif., at $163.69, and Los Angeles at $156.80. Outside of California, the highest rate was in Vancouver, Wash., where monthly rentals averaged $136.49.

Since the data looks at the average for all unit sizes, it’s important to also look at the average price per square foot. San Francisco also led in that category with an average of $3.24 per square foot. Close behind was Honolulu, Hawaii, at $3.16 per square foot and an average monthly rate of $100.51. Los Angeles was third in price per square foot at $2.66, followed by New York City (NYC) at $2.52 per square foot and an average monthly rate of $107.94.

The disparity between the average cost per square foot and the monthly total in Honolulu and NYC can be attributed to the popularity of smaller unit sizes. The average unit depth in Honolulu was 6.3 feet. In New York it was 7.3 feet. Compare that to depth averages in San Francisco and Los Angeles, which were 8 feet and 8.8 feet, respectively.

On the other end of the spectrum, Oklahoma City, Okla., had the lowest average rental rates in the top 200 markets at $52.51 per month. Rounding out the bottom were Montgomery, Ala., at $53.07 and Lubbock, Texas, at $54.36.

Cities with monthly rates closest to the national average of $91.14 included:

View data for all 200 markets in the analysis here.

Alexander Harris is editor of the “SpareFoot Storage Beat” blog published by SpareFoot.com. He obtained his degree in journalism from Virginia Commonwealth University. He loves reading Elmore Leonard novels and listening to classic country music. SpareFoot helps consumers find and reserve self-storage units, with comparison shopping tools that show real-time availability and exclusive deals.