What is the instantaneous rate of the reaction at t=800. s ? and the units please?

An average reaction rate is calculated as the change in the concentration of reactants or products over a period of time in the course of the reaction. An instantaneous reaction rate is the rate at a particular moment in the reaction and is usually determined graphically.
The reaction of compound forming compound was studied and the following data were collected
Time (s)
0. 0.184
200. 0.129
500. 0.069
800. 0.031
1200 0.019
1500 0.016

average reaction rate between 0 and 1500 is 1.12*10 to the negative fourth. M/s
average reaction rate between 500 and 1200s is 7.14 *10 to the negative fifth