A conventional drained triaxial compression test was conducted on a normally consolidated clay sample under an effective confining pressure of $200$ kPa. The deviator stress at failure was found to be $400$ kPa. An identical specimen of the same clay sample is isotropically consolidated to a confining pressure of $200$ kPa and subjected to standard undrained triaxial compression test. If the deviator stress at failure is $150$ kPa, the pore pressure developed (in kPa, up to one decimal place) is ________