  High quality observations of the low degree p-modes exist for almost two
complete solar cycles using the solar spectrophotometer Mark-I, located and
operating at the Observatorio del Teide (Tenerife, Spain). In this work, the
observations available have been re-analyzed over a much wider time interval
than before. We analyze the time variation of the yearly frequency shift and
its frequency dependence. This information will be used in order to average
annual power spectra by removing the effect of the solar cycle. Using this
average power spectrum, a new estimate of the rotational splittings is
attempted.
