  We investigate the distribution of fluctuations in solar irradiance when
integrated over the full disk, obtained using extreme ultraviolet/soft X-ray
observations from the SOHO CELIAS/SEM instrument. This time series sums over
both the contributions of single distinguishable flares, and of many other
processes. By detrending we select events with timescales of less than a few
hours such as waves, slow flows, and CMEs. The statistics generated by this
range of phenomena can be characterised by power-law-tailed distributions. We
show that (i) during the high-activity period 2000 Jan-June the tail exponent
a(T)=1.5 +/- 0.1; (ii) during the low-activity period 1996 Jan-June a(T)=3.0
+/- 0.2; and (iii) in general a(T) decreases with increasing activity.
