The Genotypes and Numbers of Progeny Resulting from a Testcross

Essay

The genotypes and numbers of progeny resulting from a testcross are as follows:
$\begin{array} { l r } t ^ { + g {+} l {+} }& 72 \\t g l & 69 \\t ^ { + g l } & 21 \\\operatorname { tg }^{ + l + }& 18 \\t ^ { + g l +} & 9 \\\operatorname { t}{g } ^+ l & 8 \\t ^ { +g + l }& 2 \\\text { tg}l^{+} & 1 \\\text { Total } & 200\end{array}$
Calculate the genetic distance between genes g and l.