  In this study, we used two methods to investigate the periodic behavior of
sunspot counts in four categories for the time period January 1986-October
2013. These categories include the counts from simple (A and B), medium (C),
large (D, E, and F), and final (H) sunspot groups. We used: i) the Multi-taper
Method with red noise approximation, and ii) the Morlet wavelet transform for
periodicity analysis. Our main findings are: (1) the solar rotation periodicity
of about 25 to 37 days, which is of obvious significance, is found in all
groups with at least a 95% significance level; (2) the periodic behavior of a
cycle is strongly related to its amplitude and group distribution during the
cycle; (3) the appearance of periods follow the amplitude of the investigated
solar cycles, (4) meaningful periods do not appear during the minimum phases of
the investigated cycles. We would like to underline that the cyclic behavior of
all categories is not completely the same; there are some differences between
these groups. This result can provide a clue for the better understanding of
solar cycles.
