Found a good place to get long term dividend data. On Yahoo Finance go to historical prices (upper left). Once you're there click on "dividends only" on the right side. Then hit "get prices" to get a good listing of historical div. amounts and X-div. dates.
also of worth ....the DECLARATION dates help give idea of when co will declare....by going to calendar and finding day of week and time of month....can come close to prdicting declare date ..use this a lot to anticipate 'action'....not avialable on most sites....the more to 'average' the better the results....here is one for HYF: