$\text{ If }{\mathrm{a}}_1,{\mathrm{a}}_2,{\mathrm{a}}_3,5,4,{\mathrm{a}}_6,{\mathrm{a}}_7,{\mathrm{a}}_8,{\mathrm{a}}_9\text{ are in H.P., and }\mathrm{D}=\left|\begin{array}{ccc}{\mathrm{a}}_1& {\mathrm{a}}_2& {\mathrm{a}}_3\\ 5& 4& {\mathrm{a}}_6\\ {\mathrm{a}}_7& {\mathrm{a}}_8& {\mathrm{a}}_9\end{array}\right|\text{, then the value of }\left[\mathrm{D}\right]$ $\text{ is (where [.] represents the greatest integer function) }$