If $\mathrm{\alpha },\mathrm{\beta },\mathrm{\gamma },\mathrm{\delta }\in \mathrm{R}\text{ satisfy }\frac{{(\mathrm{\alpha }+1)}^2+{(\mathrm{\beta }+1)}^2+{(\mathrm{\gamma }+1)}^2+{(\mathrm{\delta }+1)}^2}{\mathrm{\alpha }+\mathrm{\beta }+\mathrm{\gamma }+\mathrm{\delta }}=4$ if biquadratic equation ${\mathrm{a}}_0{\mathrm{x}}^4+{\mathrm{a}}_1{\mathrm{x}}^3+{\mathrm{a}}_2{\mathrm{x}}^2+{\mathrm{a}}_3\mathrm{x}+{\mathrm{a}}_4=0$has the roots $(\mathrm{\alpha }+\frac{1}{\mathrm{\beta }}-1),(\mathrm{\beta }+\frac{1}{\mathrm{\gamma }}-1),(\mathrm{\gamma }+\frac{1}{\mathrm{\delta }}-1),(\mathrm{\delta }+\frac{1}{\mathrm{\alpha }}-1)$. Then the value of a₂ / a₀ is