I would like to hire an Excel Expert

Active spreadsheet that has check boxes. Used for assessing the condition of a product (sail) in a service environment. There are 19 separate areas that have a condition report associated, functioning as a checkbox. These check boxes are nubered 5, 4, 3, 2, 1, & 0 These need to have a value attached, being 100, 80, 60, 40, 20, 00. When the check boxes all have all been ticked (activated), the sheet needs to generate an average value for all check boxes, and then display this score as a percentage. This average also needs to announce an Overall Rating, based on the average. There are 2 sections that have a simple Yes / No activation, they are not to be attributed numeric values. Leave as they are. I have done the layout, and need only to activate the check boxes and average. It needs to be able to be used on an Ipad (if possible) and android tablet. I have attached the Spreadsheet and also a pdf of the finished layout. If you have suggestions for a better user interface I would like to hear it, but it needs to stay as a single page for ease of use and printing.