计算不同时间步长的堆栈栅格中的均值，中值和标准差

I have a raster brick/stack (using the raster package) in R for 45 years of annual rainfall data from 1970 to 2015. I want to calculate mean, median and standard deviation for a given year e.g. 2015 using the last 5 years, 10 years, 15 years, 20 years, 30 years. I want to do it from 2000 to 2015, where this processes repeated for every year using the stacked data and save the newly derived rasters for a given year. This the example code. Any help is greatly appreciated. I have a raster brick/stack (using the raster p