In a catchment area, four rain gauging stations namely A, B, C and D are installed. Rain gauge C was inoperative for a particular year, during which the rain gauge A, B and D recorded 90 cm, 60 cm and 70 cm depth of precipitation respectively. Estimate the missing rainfall at data (in cm), if the annual average data of four stations A, B, C and D is 60 cm, 75 cm, 80 cm and 100 cm respectively.