Given the task definition and input, reply with output. In this task you are given a list of numbers and you need to find the average of each two consecutive values. The average of two numbers a and b is calculated as: (a + b) /2. The output should be a list of the averages of each two consecutive values. A list is presented with two brackets and comma-separated values, like: [1,2,3].

[-39, -70, -70, 14, -23, 55, 99, -82, -98, -69, -35, 31]

[-54.5, -70.0, -28.0, -4.5, 16.0, 77.0, 8.5, -90.0, -83.5, -52.0, -2.0]