Analog read value inconsistent

Here is a reading with the meter connected and working:
Analog Val: 222
Analog Val: 244
Analog Val: 227
Analog Val: 236
Analog Val: 235
Analog Val: 215
Analog Val: 232
Analog Val: 226
Analog Val: 226
Analog Val: 212

Disconnecting the Display:
Analog Val: 201
Analog Val: 201
Analog Val: 201
Analog Val: 202