The level of activity of the customers on the banking market is one of the measurements of demand for financial services. It allows one to better understand the changes on the banking market. The objective of this paper is to identify and evaluate the changes in the level of activity of bank customers in the segment of cooperative banks. The analysis includes the level of activity of the individual customers as well as entrepreneurs on the deposit and credit markets in the years 1994-2014. The analyses used the Census X-11 method as well as the Fast Fourier Transform analysis. The level of activity of the customers of cooperative banks undergoes periodic fluctuations. The cycle and intensity of these fluctuations is different for the deposit and for credit markets. The deposit market is dominated by the periodical cycles and the credit market by seasonality. Accidental factors play a surprisingly high role in the changes of the activity levels of the cooperative bank customers.