  Radiative decay from the excited $^1P_1$ state to metastable $^3P_2$ and
$^3P_0$ states is expected to limit attainable trapped atomic population in a
magneto-optic trap of ytterbium (Yb) atoms. In experiments we have carried out
with optical repumping of $^3P_{0,2}$ states to $^3P_1$, we observe enhancement
of trapped atoms yield in the excited $^1P_1$ state. The individual decay rate
to each metastable state is measured and the results show an excellent
agreement with the theoretical values.
