How to calculate a Voltage divider's resistance values from a required current
If you estimate the Hfe of the transistor as 100 then 70mA Ice requires 700uA Ibe.  Assuming that the Vbe drop will be about 700mV, the 200R resistor will draw 3.5mA and so the more positive part of the potential divider needs to supply 4.2mA.  It has a voltage drop of 11.3V (12 - 0.7) and so the resistance should be 2690R.  The Hfe of the transistor may be significantly different from this, but since the majority of the divider current flows through the 200R resistor, the circuit won't be particularly sensitive to the Hfe.